Wireless system to power a low current device

ABSTRACT

A wireless system comprising a first wireless device and a second wireless device. The first wireless device is configured to operate with less than 15 milliamperes of current. The second wireless device has an internal power source and is configured to transmit one or more radio frequency signals to the first wireless device. The first wireless device is configured to receive the one or more radio frequency signals from the second wireless device. The first wireless device is configured to harvest energy from the one or more radio frequency signals. The first wireless device is enabled for operation after a predetermined amount of energy is harvested from the one or more radio frequency signals. A communication handshake occurs between the first and second wireless devices to indicate that the first wireless device is in communication with the second wireless device. The first wireless device is configured to perform at least one task from harvested energy.

FIELD

The present invention pertains generally to medical devices, andparticularly to, but not exclusively to, an orthopedic system forgenerating measurement data to assess a musculoskeletal system.

BACKGROUND

Wireless technology has advanced significantly in recent years.Different types of wireless technology are ubiquitous having industrystandards that allow companies to use the communication technologyseamlessly. Wireless standards such as WiFi, Bluetooth, WiMax, Zigbee,Wireless Mesh Networks, and Cell phone standards are available andintegrated in many commonly used devices. People using wireless devicescan be in areas of high signal traffic with different networks incommunication with devices. For example, a home can have cell phonecoverage, a wireless local network, a WiFi hot spot, Bluetoothconnections, Zigbee connections, and others. Thus, the home can haveaccess to many different radio frequency signals in different frequencybands for interconnection. It should be noted that many devices connectto a wireless device via a wired connection. Some of these devicesrequire a current “low current” less than 15 milliamperes for operation.It would be of great benefit if these “low current” devices could be madwireless at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features of the system are set forth with particularity in theappended claims. The embodiments herein, can be understood by referenceto the following description, taken in conjunction with the accompanyingdrawings, in which:

FIG. 1A is an illustration of a smart screw in accordance with anexample embodiment;

FIG. 1B is a top view of the smart screw in accordance with an exampleembodiment;

FIG. 1C is an illustration of a smart screw in accordance with anexample embodiment;

FIG. 1D is an illustration of a smart screw in accordance with anexample embodiment;

FIG. 1E is an illustration of a smart screw in accordance with anexample embodiment;

FIG. 1F is an illustration of a smart screw in accordance with anexample embodiment;

FIG. 1G is an illustration of a smart screw having a dual channel inaccordance with an example embodiment;

FIG. 1H is an illustration of a smart screw and a washer in accordancewith an example embodiment;

FIG. 1I is an illustration of a washer in accordance with an exampleembodiment;

FIG. 1J is an illustration of the washer and the smart screw inaccordance with an example embodiment;

FIG. 2 is an illustration of components used in a smart screw system inaccordance with an example embodiment;

FIG. 3A is an illustration of a smart screw system in accordance with anexample embodiment;

FIG. 3B is an illustration of a smart screw system in accordance with anexample embodiment;

FIG. 4A is an illustration of a top view of a washer system inaccordance with an example embodiment;

FIG. 4B is a lateral view of the washer system in accordance with anexample embodiment;

FIG. 5A is an illustration of a plurality of smart screws configured tocommunicate to a computer in accordance with an example embodiment;

FIG. 5B is an illustration of a plurality of smart screws with aplurality of smart washers in communication with one another inaccordance an example embodiment;

FIG. 6A is an illustration of a smart plate in accordance with anexample embodiment;

FIG. 6B is an illustration of the plate coupled to a bone in accordancewith an example embodiment;

FIG. 7A is an illustration of a handle in accordance with an exampleembodiment;

FIG. 7B is an illustration of a percutaneous screw in accordance with anexample embodiment;

FIG. 7C is an illustration of the handle coupled to the percutaneousscrew in accordance with an example embodiment;

FIG. 7D is an illustration of the handle removed from the percutaneousscrew after being screwed into the bone in accordance with an exampleembodiment;

FIG. 8 is an illustration of an orthopedic measurement system inaccordance with an example embodiment;

FIG. 9 is an illustration of communication paths of an orthopedicmeasurement system in accordance with an example embodiment;

FIG. 10 is an illustration of electronic circuitry for two waycommunication configured to receive energy to support internal powering,or configured to transmit energy to power another device in accordancewith an example embodiment;

FIG. 11 is an illustration of a device in accordance with an exampleembodiment;

FIG. 12 is an illustration a partial view of a subcutaneous screw inaccordance with an example embodiment;

FIG. 13 is an illustration of a screw housing in accordance with anexample embodiment;

FIG. 14 is an illustration of a partial screw in accordance with anexample embodiment;

FIG. 15A is an exploded view of the device with a plurality of sensorsconfigured to measure one or more parameters in accordance with anexample embodiment;

FIG. 15B is an exploded view of the device with the plurality of sensorsconfigured to measure one or more parameters in accordance with anexample embodiment;

FIG. 15C is a view of an underside of the device with the plurality ofsensors exposed for measurement to an external environment in accordancewith an example embodiment;

FIG. 16 is an illustration of a system using the electronic circuitryconfigured to charge a device in accordance with an example embodiment;

FIG. 17 is an exploded view of the device in accordance with an exampleembodiment;

FIG. 18 is an illustration of the electronic circuitry placed in thehousing that couples to the device of FIG. 17 in accordance with anexample embodiment;

FIG. 19 is an illustration of two antennas formed on the same substratein accordance with an example embodiment;

FIG. 20 is a list of specifications for the antennae of FIG. 19 inaccordance with an example embodiment;

FIG. 21 is an illustration of impedance tuning and frequency tuning ofthe antennae of FIG. 19 in accordance with an example embodiment;

FIG. 22 is an illustration of a measurement of the antennae of FIG. 19in accordance with an example embodiment;

FIG. 23 is an illustration a radiation pattern for the antennae of FIG.19 in accordance with an example embodiment;

FIG. 24 is a block diagram of a system in accordance with an exampleembodiment;

FIG. 25 is a block diagram illustrating two or more channels beingtransmitted from the devices of FIG. 24 in accordance with an exampleembodiment;

FIG. 26 is a block diagram of circuitry within the devices of FIG. 24 tosupport energy harvesting in accordance with an example embodiment; and

FIG. 27 is a block diagram illustrating a horizontal and verticalantenna array controlled by a microprocessor in accordance with anexample embodiment.

DETAILED DESCRIPTION

The following description of exemplary embodiment(s) is merelyillustrative in nature and is in no way intended to limit the invention,its application, or uses.

Processes, techniques, apparatus, and materials as known by one ofordinary skill in the art may not be discussed in detail but areintended to be part of the enabling description where appropriate.

While the specification concludes with claims defining the features ofthe invention that are regarded as novel, it is believed that theinvention will be better understood from a consideration of thefollowing description in conjunction with the drawing figures, in whichlike reference numerals are carried forward.

The example embodiments shown herein below of the device areillustrative only and do not limit use for other parts of a body or forother applications. The device is used to measure at least parameter togenerate quantitative measurement data. The devices disclosed hereinbelow are configured to support health, healing, and generatequantitative measurement data related to the human body. In oneembodiment, the device is configured to couple to a musculoskeletalsystem is used on the knee, hip, ankle, spine, shoulder, hand, wrist,foot, fingers, toes, bone, muscle, ligaments tendon and other areas ofthe musculoskeletal system. Although one or more examples may describeuse on the musculoskeletal system the principles disclosed herein aremeant to be adapted for use to all locations on or within the humanbody. The following description of embodiment(s) is merely illustrativein nature and is in no way intended to limit the invention, itsapplication, or uses.

For simplicity and clarity of the illustration(s), elements in thefigures are not necessarily to scale, are only schematic and arenon-limiting, and the same reference numbers in different figures denotethe same elements, unless stated otherwise. Additionally, descriptionsand details of well-known steps and elements are omitted for simplicityof the description. Notice that once an item is defined in one figure,it may not be discussed or further defined in the following figures.

The terms “first”, “second”, “third” and the like in the Claims or/andin the Detailed Description are used for distinguishing between similarelements and not necessarily for describing a sequence, eithertemporally, spatially, in ranking or in any other manner. It is to beunderstood that the terms so used are interchangeable under appropriatecircumstances and that the embodiments described herein are capable ofoperation in other sequences than described or illustrated herein.

Processes, techniques, apparatus, and materials as known by one ofordinary skill in the art may not be discussed in detail but areintended to be part of the enabling description where appropriate.

The orientation of the x, y, and z-axes of rectangular Cartesiancoordinates is assumed to be such that the x and y axes define a planeat a given location, and the z-axis is normal to the x-y plane. The axesof rotations about the Cartesian axes of the device are defined as yaw,pitch and roll. With the orientation of the Cartesian coordinatesdefined in this paragraph, the yaw axis of rotation is the z-axisthrough body of the device. Pitch changes the orientation of alongitudinal axis of the device. Roll is rotation about the longitudinalaxis of the device. The orientation of the X, Y, Z axes of rectangularCartesian coordinates is selected to facilitate graphical display oncomputer screens having the orientation that the user will be able torelate to most easily. Therefore the image of the device moves upward onthe computer display whenever the device itself moves upward for exampleaway from the surface of the earth. The same applies to movements to theleft or right.

Although inertial sensors are provided as enabling examples in thedescription of embodiments, any tracking device (e.g., a GPS chip,acoustical ranging, accelerometer, magnetometer, gyroscope,inclinometers, or MEMs devices) can be used within the scope of theembodiments described.

At least one embodiment is directed to a kinetic orthopedic measurementsystem that is configured to measure motion and position. Themeasurement system can be used in surgery to determine real timealignment, range of motion, loading, impingement, and contact point oforthopedic implants. Although the system is generic to any orthopedicassessment, pre-operative measurement, surgery, rehabilitation, orlong-term monitoring (e.g., spinal, shoulder, knee, hip, ankle, wrist,finger, toe, bone, musculoskeletal, etc.) the following examples dealwith the use in the orthopedic field as a non-limiting example of anembodiment of the invention.

The non-limiting embodiment described herein is related to quantitativemeasurement used for orthopedic assessment and referred to herein as thekinetic system. The kinetic system includes a sensor system thatprovides quantitative measurement data and feedback that can be providedvisually, audibly, or haptically to a patient, doctor, medical staff,therapist, surgeon or surgical team. The kinetic system providesreal-time dynamic data regarding sensor information and positioninformation related to the musculoskeletal system.

In general, kinetics is the study of the effect of forces upon themotion of a body or system of bodies. Disclosed herein is a system forkinetic assessment of the musculoskeletal system. The kinetic system canbe for monitoring and assessment of the musculoskeletal system orinstalled prosthetic components coupled to the musculoskeletal system.For example, installation of a prosthetic component can require one ormore bone surfaces to be prepared to receive a device or component. Thekinetic system is designed to take quantitative measurements related tomovement of one or more bones of the musculoskeletal system, takemeasurements from one or more sensors to monitor health, or providetherapy to support healing. The sensors are designed to allow ligaments,tissue, and bone to be in place while the quantitative measurement datais taken. This is significant because the bone cuts take into accountthe kinetic forces where a kinematic assessment and subsequent bone cutscould be substantial changed from an alignment, load, and position ofload once the joint is reassembled. In one embodiment, one or morescrews can be implanted in one or more bones to provide measurementdata. Alternatively, one or more sensors can be coupled to the skin as aflexible patch. In one embodiment, the implanted screws can be incommunication with the implanted screws as a system working together toin a specific application.

A prosthetic joint installation can benefit from quantitativemeasurement data in conjunction with subjective feedback of theprosthetic joint to the surgeon. Pre-operative measurement data can becollected to provide a pathology of a patient and set expectations andoutcomes from a surgical or prosthetic component solution. Thequantitative measurements can be used to determine adjustments to bone,prosthetic components, or tissue prior to final installation. Permanentsensors can also be housed in final prosthetic components to provideperiodic data related to the status of the implant. Data collectedintra-operatively and long term can be used to determine parameterranges for surgical installation and to improve future prostheticcomponents. One or more sensors used post-operatively can be used tomonitor motion of the musculoskeletal system to determine how the repairis performing and provide feedback based on quantitative measurementdata. The physical parameter or parameters of interest can include, butare not limited to, measurement of alignment, load, force, pressure,position, displacement, density, viscosity, pH, spurious accelerations,color, movement, chemical composition, particulate matter, structuralintegrity, and localized temperature. Often, several measured parametersare used to make a quantitative assessment. A graphical user interfacecan support assimilation of measurement data. Parameters can beevaluated relative to orientation, alignment, direction, displacement,or position as well as movement, rotation, or acceleration along an axisor combination of axes by wireless sensing modules or devices positionedon or within a body, instrument, appliance, equipment, or other physicalsystem.

At least one embodiment is directed to a system for adjusting ormonitoring position of the musculoskeletal system for stability,alignment, balance, and range of motion. Examples of monitoring cancomprise: a prosthetic component configured to rotate after beingcoupled to a bone; a sensored prosthesis having an articular surfacewhere the sensored prosthesis is configured to couple to a secondprosthetic component, the sensored prosthesis has a plurality of loadsensors coupled to the articular surface and a position measurementsystem configured to measure position, slope, rotation, or trajectory, aremote system configured to wirelessly receive quantitative measurementdata from the sensored prosthesis where the remote system is configuredto display the articular surface, where the remote system is configuredto display position of applied load to the articular surface, and wherethe remote system is configured to report impingement as themusculoskeletal joint is moved through a range of motion (ROM).

Embodiments of the invention are broadly directed to measurement ofphysical parameters. Many physical parameters of interest withinphysical systems or bodies can be measured by evaluating changes in thecharacteristics of energy waves or pulses. As one example, changes inthe transit time or shape of an energy wave or pulse propagating througha changing medium can be measured to determine the forces acting on themedium and causing the changes. The propagation velocity of the energywaves or pulses in the medium is affected by physical changes in of themedium. The physical parameter or parameters of interest can include,but are not limited to, measurement of load, force, pressure,displacement, density, viscosity, localized temperature. Theseparameters can be evaluated by measuring changes in the propagation timeof energy pulses or waves relative to orientation, alignment, direction,or position as well as movement, rotation, or acceleration along an axisor combination of axes by wireless sensing modules or devices positionedon or within a body, instrument, appliance, vehicle, equipment, or otherphysical system.

In all of the examples illustrated and discussed herein, any specificmaterials, temperatures, times, energies etc. . . . for process steps orspecific structure implementations should be interpreted to beillustrative only and non-limiting. Processes, techniques, apparatus,and materials as known by one of ordinary skill in the art may not bediscussed in detail but are intended to be part of an enablingdescription where appropriate.

Note that similar reference numerals and letters refer to similar itemsin the following figures. In some cases, numbers from priorillustrations will not be placed on subsequent figures for purposes ofclarity. In general, it should be assumed that structures not identifiedin a figure are the same as previous prior figures.

In the present invention these parameters are measured with anintegrated wireless sensing module or device comprising an i)encapsulating structure that supports sensors and contacting surfacesand ii) an electronic assemblage that integrates a power supply, sensingelements, ultrasound resonator or resonators or transducer ortransducers, an accelerometer, antennas and electronic circuitry thatprocesses measurement data as well as controls all operations of energyconversion, propagation, and detection and wireless communications. Thewireless sensing module or device can be positioned on or within, orengaged with, or attached or affixed to or within, a wide range ofphysical systems including, but not limited to instruments, appliances,vehicles, equipments, or other physical systems as well as animal andhuman bodies, for sensing and communicating parameters of interest inreal time.

While the present invention has been described with reference toparticular embodiments, those skilled in the art will recognize thatmany changes may be made thereto without departing from the spirit andscope of the present invention. Each of these embodiments and obviousvariations thereof is contemplated as falling within the spirit andscope of the invention.

One type of orthopedic screw is an ACL (Anterior Cruciate Ligament)screw. One or more ACL screws are placed during ACL reconstruction tostabilize the ligament in the femur and in the proximal tibia. Thehardware can be a metal based interference screw such as titanium,plastic such as PEEK, or bio-absorbable. A screw is placed duringsurgery and typically is not removed even after healing unless afailure, soft tissue impingement, or reconstructive implants requireremoval of the screw. A smart screw is a screw that housesmicro-electronics that performs one or more functions. In oneembodiment, the smart screw is used during surgery to aid in screwplacement and screw graft stabilization.

A smart screw intra-operative system can incorporate microelectronicintegration into an arthroscopic system. There is a need for appropriatetunnel placement in the tibia and femur to support healing andpost-operative function. Problems can occur if the graft is placedinappropriately causing impingement, pain limited range of motion, andgraft failure. In one embodiment, the surgeon can place a small smarttack (fiducial) in the intra-articular non-loaded area of the femur andone in the tibia. The arthroscope utilizing optics, registers thefiducials relative to the femoral and tibial bone model of the patient.A pre-operative MRI can be utilized or an intra-operative ultra-scan toregister femur and tibia to the optical system. In the example, thesmart screw will have IMU (inertial measurement unit) electronics willbe referenced from the fiducials and tracked along their insertion path,to define depth and angles of the smart screw placement. The smart screwor a device can include one or more MEMs (micro-electro-mechanicalsystems) devices, a camera, or video device. The device can be tool usedin conjunction with the screw. The smart screw as it is being insertedwill measure the torque required and confirm that the screw is securelystabilized. In the example, measurement data from the screw or devicecan be transmitted to a computer having a display to provide themeasurement data in real-time.

Once the smart screws are placed in the tibia and femur, they are zeroedrelative to gravity and each other. The knee is taken through a fullROM, full extension, and defined flexion is recorded by the system.Measurement data related to rotation and dynamic stresses related totranslation are now recorded by the system. An anterior-posterior draweris performed where the knee is flexed 90 degrees and a force applied tothe tibia in the posterior and then in the anterior direction. Thetranslation and displacement of the knee is recorded relative to the atleast two smart screws. A Lachman Test can also be performed where theknee is flexed 20 degrees and the tibia is pulled forward to assess theamount of anterior motion of the tibia to define ACL stability.Similarly, medial-lateral forces can be applied at 20 degrees to definecollateral ligament stability.

The smart screws are also used for post-operative monitoring. First, thesmart screws can be used to identify if the patient post-operativetherapy is progressing appropriately. In one embodiment, the patient isdischarged with crutches and a brace. Physical Therapy is institutedwithin several days of surgery. Limited weight bearing is controlled toprotect the ACL until interval healing has occurred and the patient'squadriceps function and knee stability has returned. The knee ismonitored for infection and resolution of swelling and inflammation.Compliance to the prescribed post-op regimen can be monitored. Anexercise regimen can be sent to the patient's phone and the smart screwsactivated to monitor that the patient is following protocol and remainsin a “safe” healing zone. The knee brace can house the near field energysource to energize the electronics, and the knee function can then beinterrogated.

Placement of the smart screws in the femur and tibia are used todescribe knee function. For example, the smart screws can monitor andmeasure ROM (range of motion) relative to gravity and Femur to Tibia.The smart screws can be used to measure quadriceps strength and torquewith a defined extension maneuver with applied resistance. Gaitmechanics such as stride, cadence, activity, steps and other movementcan be monitored by the smart screws. As previously mentioned, theLachman test can be monitored by the smart screws by measuring anteriormotion of the tibia in a predetermined movement of the tibia in relationto the femur. Another test that generates quantitative measurement datafrom the smart screws is an anterior-posterior drawer. The knee isflexed 90 degrees and a force is applied to the tibia in the posterior.The anterior direction translation and displacement of the knee ismeasured and recorded relative to the smart screws. All of the abovequantitative measurement data is used to support assessment of thepatient post-operatively. The measurement data can indicate ifadjustments to the therapy are required and the status of the implantedprosthetic components.

In the example of a knee joint, the quantitative measurement data fromthe smart screws can indicate stable knee function. The patient can thenbe released from using crutches and later bracing can be considered tosupport the knee joint for optimal operation. The effects of the therapyprogram using the smart screws can be linked to knee function and apatient can be educated on their recovery relative to a plan and otherpatients. In one embodiment, when the smart screw is activated, the datawill be transmitted (RF/Bluetooth) to a patient recovery application. Inone embodiment, the application can be on a computer or a device such asa smart phone. The quantitative measurement data from the smart screwswill be uploaded into a cloud based VPN (virtual private network) thatis HIPPA Compliant. The quantitative measurement data can be assessed byone or more computer programs and updates, work flows, and themeasurement data can be sent to the treating physician and health careteam. The smart screws can be used to support post-op exercises,treatment, or pharmaceuticals that can accelerate the healing phase.Furthermore, different ACL reconstruction techniques can be comparedwith real-time data. Evaluations of the effects of ACL reconstructionwhen combined with multi ligamentous injuries can also be analyzed.Healing phase monitoring related to graft adherence to the host tunnels(bone to bone, tendon to bone, composite to bone) can providequantitative measurement data related thereto. Other importantparameters can also be generated such as improving ROM and terminalextension, achieving improved muscle strength, improved proprioception,improved stability, and improved gait mechanics.

The smart screws can also be used to determine when the “patient” ishealed. For example, quantitative measurement data from the smart screwscan be used to determine if an ACL is healed so that the patient canreturn to high intensity activities. Presently, a patient exam is oftenused after a predetermined time after surgery to release a patient tosports. The patient exam is a subjective examination that can vary fromsignificantly between surgeons and doctors. There is very littleobjective data that is utilized to define when functional healing hasoccurred. A quantitative functional knee exam can be performed with theactivated smart screws relaying the information in real-time. Furtherevaluation, can be assessed while the patient is placed in a walkingregimen, then a running regimen, followed to sports relatedacceleration—deceleration activities where data is being generated bythe smart screws. In one embodiment, the smart screws will send datarelated to the knee function to a data base for evaluation by one ormore programs that use the quantitative measurement data to provide afunctional knee determination based on measurement data of a healedfunctional knee that can be used with a subjective examination.

The smart screws can also be used to evaluate post-operative exercises,post-operative treatment, or pharmaceuticals where measurement dataprovides evidence of the efficacy of the different treatments. Differenttechniques to reconstruct the musculoskeletal system can also beevaluated. For example, different ACL reconstruction techniques can becompared with real-time data to evaluate the effects of ACLreconstruction when combined with multi ligamentous injuries. In oneembodiment, the healing phase monitoring is related to the graftadherence to the host tunnels such as bone to bone, tendon to bone, orcomposite to bone. Other important parameters can also be monitored tosee the efficacy of the treatments to improve range of motion, terminalextension, muscle strength, improved proprioception, improved stability,or improved gait mechanics.

The smart screws can also be used for long term monitoring. An extremeexample is an athlete returning back to a sport. For example, a kneejoint can be monitored for skeletal knee stability related to strength.The torque and range of motion can be monitored during specific trainingor activities that are deemed essential. The measurement data can beanalyzed from the smart screws that lead to specific interventions thatcan be utilized if knee stability is decompensating. Furthermore if theathlete fells that a sprain or injury occurred and wants to continueplaying, the screw can be activated and the knee mechanics and kineticsof the leg and joint can be evaluated. Although the example is a kneejoint it should be noted that the use of smart screws can be used forany joint or part of the musculoskeletal system.

As previously mentioned, there are many different types of sensors thatcan be utilized within a smart screw. In one embodiment, the smartscrews can be used for the treatment of disease or apply a treatment ordrug. For example, the smart screw can include an ultrasonic sensor thatcan be utilized to generate frequencies to aid in healing through bloodflow modulation, and osteoplastic induction. The smart screw has theability for in vivo monitoring of multiple parameters with multiplesensors. The stability of the screw smart implantation can be monitoredto measure local bone softening due to blood flow and final healing ofgraft. The stability of a joint related to motion, rotation,translation, and range of motion. From a macro perspective, the smartscrews can be used to monitor the musculoskeletal system to providemeasurement data related to joint mechanics as muscle strength changes,gait mechanics, compliance to rehabilitation program (frequency, effort,protection), general activity, patient directed interrogation of themusculoskeletal system, and physician interrogation of themusculoskeletal system related to a joint, rehabilitation, and sports.

As shown herein above, smart screws can be placed in the femur and tibiato provide quantitative measurement data that can be used in a varietyof ways to assess the musculoskeletal system and more specifically aknee joint replacement and subsequent rehabilitation of the leg. Ingeneral, smart screws will be used in the sports medicine to assess themusculoskeletal system, repair, and rehabilitate using quantitativemeasurement data. The measurement data on the knee, hip, and rotatorcuff, shoulder, and other musculoskeletal repairs can be used to ensurethat the subject is prepared and ready for sustained physical activity.

Smart screws can be used in trauma applications such as hip-pelvis,spine, and extremity fractures. Hip fractures can be stabilized with ascrew attached to a rod or plate. The smart screw can aid in providingmeasurement data related to the internal stability of the bone whenplacing the screw. Post-operatively, the smart screw can be used tomonitor healing of the fracture. The smart screw will housemicro-electronics, sensors, communication circuitry, and logic tocontrol a measurement process. In one embodiment, the smart screw willinclude micro-motion related sensors. Signals can be sent through thefracture side to be detected by micro-motion sensors to determine theeffects of weight bearing on the fracture. Surgeons can refine thepatient's post-operative activities and gait mechanics during thehealing process. Moreover, the surgeon or doctor can assure the patientwith quantitative measurement data related to their progress and sendactivity strengthening exercises related to gait or strength to meet theneed of the patient.

The smart screws can be used to detect motion at an implant to boneinterface or bone to bone interface. For example, smart screws can beused to detect motion in the spine between an implant and vertebrainterface. In spinal surgery, implants such as inter-body fusion cagesand disc replacement prostheses are often used. In most fusion orcorrective spinal procedures, pedicle screws are used. Spinal painfollowing fusions, disc replacements, and other procedures can stem frompersistent motion at what should be a stable interface. In certaininstances a surgeon wants the ability to detect motion at an implant orbone interface. An example of movement is when a spinal segment isfused; the forces are then transferred to the surrounding soft tissueand vertebral levels above and below. Proximal Junctional Kyphosis, iswhere the spinal segment above and/or below the fused segment becomesunstable can occur asymptomatically. Further surgery may be requiredwhen symptoms occur, to stabilize the segment. This can occurcontinuously throughout the patient's life. Currently, it is difficultto identify the cause of significant post-operative spinal pain.Abnormal motion is currently evaluated by standard and dynamic motionX-rays, and nuclear imaging. Presently there is no accurate way toconfirm abnormal motion at these interfaces with a high sensitivity andspecificity. Moreover, a surgeon desires the ability to avoid surgicalexploration of the fusion or disc implant site to confirm abnormalmotion.

The smart screw is an implantable sensor system that is applied at thebone-implant surface. Since a spinal fusion requires integration of the“cage” or spinal instrumentation into the fusion mass, a sensor that isincorporated into the “cage” or instrumented elements can detect motion.In non-instrumented fusions, the sensors can be implanted into the bonyelements at specific locations to detect abnormal motionpost-operatively. In one embodiment, a spinal implant such as the smartscrew is inserted into the pedicle of a spinal bone. The smart screwwill house the micro-electronics. The smart screw is activated with oneor more sensors that measures position in 3D space and trajectory suchthat the smart screw can be guided into appropriate angles and depthwithin bone. The smart screw will be placed then tested for stabilityand torque to confirm the smart screw is fully seated. Each spinalsegment will house at least 2 smart screws and one smart screw can beplaced into the spinal segment above and below the surgical segments.Post-operatively, the sensors in each smart screw can be activated orpowered by an external mechanism. For example power can be providedinductively or by radio frequency signals to provide power that enablesthe smart screws for providing quantitative measurement data. Acapacitor or energy storage device can store the energy for use at alater time period or when activated. Power management circuitry can beused to reduce energy consumption. Alternatively, the smart screw couldhouse an energy source such as a battery. Once the smart screws areactivated, the patient would flex, extend, rotate and load the sensorsin the smart screws at variable positions. In one embodiment, the sensorinformation would be transmitted from the smart screws and received byan external computer with a display. The computer can include softwareto analyze the quantitative measurement data, display the measurementdata, or the measurement data can be translated in a graphic form tosupport rapid assimilation of the information. The surgeon can nowdocument the amount of motion and load at a fusion site or disc implantinterface. The parameters of micro-motion would then be evaluated. Inone embodiment, the computer can produce a work flow to correct theissue based on the measurement data. In general, the relative motion andthe angular changes between the smart screws would be monitored. Thepatient activities can be modified or the segment stabilized with microinvasive approaches that are minimally invasive if abnormal motion atthe surrounding segments is detected. The same technology can be used ina cage or an artificial disc motion implant.

FIG. 1A is an illustration of a smart screw 10 in accordance with anexample embodiment. Smart screw 10 is configured to house electroniccircuitry and sensors having a form factor that can be used within themusculoskeletal system. The electronic circuitry is configured totransmit measurement data and control a measurement process of thesensors. Smart screw 10 comprises a screw head 12, a shaft 14, andthreads 16. In one embodiment, electronic circuitry and sensors can beplaced within the screw head 12. A region 18 of smart screw 10 isdesigned to engage with a bit of a screw gun for screwing smart screw 10into the musculoskeletal system. The region 18 can be patterned similarto conventional screws having a slot, cross slots, hex key, or othersystems to engage a screw gun for securing smart screw 10 to themusculoskeletal system. Threads 16 are used to securely fasten smartscrew 10 to the musculoskeletal system such that smart screw 10 will notloosen under normal use of the musculoskeletal system. In oneembodiment, threads 16 will securely fasten to bone if the boneintegrity is not compromised. The screw gun or smart screw 10 can haveone or more sensors that determine stability of smart screw 10 whenfastened to the musculoskeletal system.

FIG. 1B is a top view of smart screw 10 in accordance with an exampleembodiment. Region 18 illustrates cross slots or a Phillips typecoupling. In one embodiment, screw head 12 has a cavity for housingelectronic circuitry and one or more sensors. In one embodiment, cap 19is removable to support installation of the electronic circuitry and oneor more sensors. Cap 19 is then fastened to form screw head 12 such thatthe electronic circuitry and one or more sensors are hermetically sealedwithin screw head 12. Alternatively, region 18 can be removed therebyexposing the underlying cavity for housing electronic circuitry and oneor more sensors. Region 18 can couple to and seal to cap 19 to enclosesmart screw 10. In one embodiment, the electronic circuitry and sensorscan be potted within the cavity with screw head 12 and cap 19 ismechanically engaged and sealed. In one embodiment, a glue, adhesive, orsealing material can be used in conjunction with cap 19 to form thehermetic seal.

FIG. 1C is an illustration of a smart screw 22 in accordance with anexample embodiment. Smart screw 22 comprises a screw head 24, a shaft28, and threads 34. A region 26 in screw head 24 is designed to engagewith a bit of a screw gun for screwing smart screw 22 into themusculoskeletal system. Shaft 28 is cannulated shaft. In one embodiment,electronic circuitry and one or more sensors can be placed in thecannulated shaft 28 of smart screw 22. The electronic circuitry in thecannulated shaft 28 of smart screw 22 controls a measurement process andtransmits measurement data to a computer in proximity to smart screw 22.In one embodiment, the length of shaft 28 is within a range of 2-100millimeters. In one embodiment, shaft 28 has a diameter from 2-10millimeters.

FIG. 1D is an illustration of a smart screw 36 in accordance with anexample embodiment. Smart screw 36 comprises a screw head 38, a shaft42, and threads 44. A region 40 in screw head 38 is designed to engagewith a bit of a screw gun for screwing smart screw 36 into themusculoskeletal system. Shaft 42 is divided into two sections. A section46 is a solid section of shaft 42. A section 48 is a cannulated sectionof shaft 42. In one embodiment, electronic circuitry and one or moresensors can be placed in section 48 of shaft 40. The electroniccircuitry in the cannulated shaft 42 of smart screw 36 controls ameasurement process and transmits measurement data to a computer inproximity to smart screw 36. In one embodiment, the length of shaft 42is within a range of 2-100 millimeters. In one embodiment, shaft 42 hasa diameter from 2-10 millimeters. The size of the smart screws asdisclosed applies to all screws shown herein below.

FIG. 1E is an illustration of a smart screw 50 in accordance with anexample embodiment. Smart screw 50 comprises a screw head 52, a shaft56, and threads 58. A region 54 is designed to engage with a bit of ascrew gun for screwing smart screw 50 into the musculoskeletal system.Shaft 56 is divided into two sections. A section 60 is a solid sectionof shaft 56. A section 62 is a cannulated section of shaft 56. In oneembodiment, electronic circuitry and sensors can be placed in section 62of shaft 56. The electronic circuitry in the cannulated shaft 56 ofsmart screw 50 controls a measurement process and transmits measurementdata to a computer in proximity to smart screw 50. In one embodiment,the length of shaft 56 is within a range of 2-100 millimeters. In oneembodiment, shaft 56 has a diameter from 2-10 millimeters.

FIG. 1F is an illustration of a smart screw 64 in accordance with anexample embodiment. Smart screw 64 comprises a screw head 66, a shaft70, and threads 72. A region 68 is designed to engage with a bit of ascrew gun for screwing smart screw 64 into the musculoskeletal system.In one embodiment, shaft 70 of smart screw 64 is cannulated. In oneembodiment, electronic circuitry and sensors can be placed in thecannulated shaft 70, screw head 66, or both. The electronic circuitry inthe cannulated shaft 70 of smart screw 64 controls a measurement processand transmits measurement data to a computer in proximity to smart screw64. In one embodiment, smart screw 64 can have a plurality of openings74. In one embodiment, openings 74 couple to the cannulated shaft 70 ofsmart screw 64. Opening 74 provide access to an external environmentoutside of smart screw 64 or supports placement of an object outside ofsmart screw 64. In one embodiment, openings 74 can be formed in threads72 of shaft 70. Sensors can be used to measure one or more parametersthrough openings 74.

FIG. 1G is an illustration of a smart screw 76 having a dual channel inaccordance with an example embodiment. Smart screw 76 comprises a screwhead 78, a shaft 82, and threads 84. A region 80 is designed to engagewith a bit of a screw gun for screwing smart screw 76 into themusculoskeletal system. In one embodiment, shaft 82 of smart screw 76 iscannulated. The cannulated shaft 82 is a first channel of smart screw76. In one embodiment, electronic circuitry and sensors can be placed inthe cannulated shaft 82, screw head 78, or both. The electroniccircuitry in the cannulated shaft 82 of smart screw 76 controls ameasurement process and transmits measurement data to a computer inproximity to smart screw 76. A second channel corresponds to opening 86through screw head 78. In one embodiment, the second channel can be usedfor a guide wire. Guide wires are used for drilling pilot holes in bonesto test the bone before placing screws.

FIG. 1H is an illustration of a smart screw 90 and a washer 92 inaccordance with an example embodiment. In one embodiment, washer 92couples to smart screw 90 at a head of screw 90. In one embodiment,washer 92 is fastened to smart screw 90 such that rotating smart screw90 also rotates washer 92. Alternatively, washer 92 can freely rotatearound the shaft of smart screw 90.

FIG. 1I is an illustration of a washer 98 in accordance with an exampleembodiment. A head 102 of a smart screw 96 is located centrally towasher 98. Washer 98 includes a plurality of electric channels 100. Inone embodiment, washer 98 can include one or more electronic channels100. In one embodiment, the one or more electronic channels 100 cancomprise one or more interconnects for coupling to electronic circuitryof smart screw 96 or washer 98. One or more electronic channels 100 canform part of an antenna system for transmitting or receiving data orinformation. In one embodiment, the one or more electronic channels caninclude electronic circuitry and one or more sensors.

FIG. 1J is an illustration of washer 98 and smart screw 96 in accordancewith an example embodiment. The illustration shows one or moreelectronic channels 100 on an underside of washer 98. Smart screw 96comprises head 102, shaft 104, and threads 106. Shaft 104 of smart screw96 couples through an opening of washer 98. Washer 98 couples to head102 of smart screw 96. As previously stated smart screw 96 and washer 98can house electronic circuitry and one or more sensors for generatingquantitative measurement data, monitoring the musculoskeletal system, orproviding therapy to the musculoskeletal system.

FIG. 2 is an illustration of components used in a smart screw system inaccordance with an example embodiment. In general, the components usedin the smart screw system have a small form factor configured to fitwithin a cannulated shaft or head of an orthopedic screw. A flexibleinterconnect 110 can couple to a flexible interconnect 114 by aninterconnect 112. In one embodiment, flexible interconnect 110,interconnect 112, and flexible interconnect 114 can be folded or rolledto fit within the washer or screw. Flexible interconnect 110 andflexible interconnect 114 provide area to mount and interconnectelectronic circuitry and a plurality of sensors to form a circuit.Flexible interconnect 110, interconnect 112, and flexible interconnect114 can have one or more layers to reduce a form factor. The electroniccircuitry can include digital circuitry, processors, digital logic,analog circuitry, interface circuitry, power management circuitry, andtransmit and receive circuitry. In one embodiment, the total area offlexible interconnect 110, interconnect 112, and flexible interconnect114 is approximately 1-2 millimeters square. An integrated device 116 isan energy harvesting system that is designed to generate energy to powerthe screw. Device 118 is a power source or power storage device forproviding power to the electronic circuitry and sensors. The powersource or power storage can be a battery, capacitor, inductor, or otherenergy device. In one embodiment, the integrated device 116 providespower to device 118 to recharge or refresh device 118 to provide powerwhen the electronic circuitry and sensors are enabled. Alternatively,power could be transmitted via radio frequency or coupled inductively toprovide power to device 118. Sensors coupled to the electronic circuitrycan comprise Piezo-sensors, MEMs sensors, Bio sensors, Optical Sensors,acoustical sensors, physical sensors, and environmental sensors to namebut a few.

FIG. 3A is an illustration of a smart screw system 120 in accordancewith an example embodiment. Smart screw system 120 comprises a smartscrew 128, a measurement system 130, and a computer configured toreceive measurement data. Smart screw 128 comprises a head 122, acannulated shaft 124, and threads 126. Measurement system 130 comprisesintegrated device 116, interconnect 110, interconnect 112, andinterconnect 114. Electronic circuitry and sensors can be mounted on andcoupled together to form measurement system 130 by interconnect 110,interconnect 112, and interconnect 114. In the example, the walls ofcannulated shaft 124 are transparent to show measurement system 130housed within cannulated shaft 124. Alternatively, interconnect, 110,interconnect 112, interconnect 114, and the electronic circuitry can berolled up into a cylinder to fit within cannulated shaft 124.

Integrated device 116 is an energy harvesting device that generatesenergy to power smart screw system 120. Alternatively, device 118 ofFIG. 2 could be placed within smart screw 128 in place of integrateddevice 116 to power the electronic circuitry. In one embodiment,integrated device 116 receives a radio frequency signal from an externalenvironment that is converted to power smart screw system 120. The radiofrequency signal can also contain information, data, or control signalsthat is received by smart screw system 120. Alternatively, integrateddevice 116 can harvest energy through movement or receive energyinductively. Electronic circuitry and sensors on interconnect 110,interconnect 112, and interconnect 114 controls a measurement processand transmit measurement data. The measurement process can comprisegenerating quantitative measurement data or providing therapy inproximity to smart screw system 120.

FIG. 3B is an illustration of a smart screw system 140 in accordancewith an example embodiment. Smart screw system 140 comprises a smartscrew 142, measurement system 130, and a computer configured to receivemeasurement data. Smart screw 142 comprises a head 146, a shaft 148, andthreads 150. Shaft 148 comprises a solid section 152 of shaft 148 and acannulated section 154 of shaft 148. Measurement system 130 is placed incannulated section 154 of shaft 148.

Measurement system 130 comprises integrated device 116, interconnect110, interconnect 112, and interconnect 114. Integrated device 116powers the electronic circuitry. Alternatively, device 118 of FIG. 2 canpower measurement system 130. Electronic circuitry and sensors can bemounted on and coupled together to form measurement system 130 byinterconnect 110, interconnect 112, and interconnect 114. In theexample, the walls of cannulated shaft 148 are transparent to showmeasurement system 130 housed within cannulated section 154 of shaft148. In one embodiment, interconnect 110, interconnect 112, andinterconnect 114 can be wrapped into a cylinder and placed in cannulatedshaft 114. Cannulated section 154 of shaft 148 has one or more openings156. The measurement system 144 is exposed to an external environment bythe one or more openings 156. In one embodiment, one or more openings156 expose one or more sensors of measurement system 144 to the externalenvironment.

FIG. 4A is an illustration of a top view of a washer system 160 inaccordance with an example embodiment. As shown, a smart screw 162couples to washer system 160. Alternatively, a screw could also becoupled to washer system 160. Washer system 160 comprises a washer 164and one or more measurement systems 130. As shown, washer system 160comprises two measurement systems 130. Surfaces are made transparent toshow measurement systems 130. In the example, washer 164 is cylindricalin shape having a cavity therein to place measurement systems 130.Measurement systems 130 comprise electronic circuitry and sensors asdisclosed herein. In general, each measurement system 130 can havedifferent sensors to measure different parameters, monitor activity, orprovide different therapies to the musculoskeletal system. Placingmeasurement system 130 in washer 164 supports a different location whencoupled to the musculoskeletal system for measurement when compared toplacement of measurement system 130 within a shaft of smart screw 162.Alternatively, measurement system 130 could also be placed within ascrew head or a body of smart screw 162. In one embodiment, measurementsystems 130 are in communication with a computer or other electronicdevice configured to support washer system 160 or smart screw 162. Thecomputer can analyze information provided by measurement systems 130 toassess a status of the musculoskeletal system, identifies issues withthe musculoskeletal system, and provide a workflow that supportsimprovement of the musculoskeletal system.

FIG. 4B is a lateral view of washer system 160 in accordance with anexample embodiment. In the example, washer system 160 couples to a headof smart screw 162. As shown, washer 164 includes one or moremeasurement systems 130. Surfaces are made transparent to showmeasurement systems 130. In one embodiment, washer 164 couples to asurface of the musculoskeletal system when smart screw 162 is screwedinto the musculoskeletal system. In one embodiment, washer 164 preventsor stops smart screw 162 from further penetration into themusculoskeletal system.

FIG. 5A is an illustration of a plurality of smart screws configured tocommunicate to a computer in accordance with an example embodiment. Asmart screw 170 and a smart screw 172 are coupled to a bone 176. In theexample, smart screws 170 and 172 are cannulated and each has ameasurement system 130 therein. The shafts of smart screws 170 and 172are made transparent to show measurement systems 130. In one embodiment,measurement system 130 of smart screw 170 and measurement system 130 ofsmart screw 172 is located within bone 176. Smart screws 170 and 172 arein communication with a computer 174. Smart screws 170 and 172 cancommunicate through an energy wave or pulse such as radio frequencysignals, ultra sonic signals, or electromagnetic radiation. In theexample, smart screw 170 is located farther from computer 174 than smartscrew 172. In one embodiment, smart screw 170 communicates with smartscrew 172. Smart screw 172 can store information from smart screw 170 orimmediately transmit the information from smart screw 172 to computer174. Smart screw 172 is in continuous, periodic, or random communicationwith computer 174. In one embodiment, smart screw 172 transmits andreceives information with computer 174. The information that smart screw172 transmits to computer 174 can include information or measurementdata from smart screw 170. Similarly, some information transmitted fromcomputer 174 to screw 172 can be transmitted to smart screw 170.Computer 174 can display measurement data from smart screws 170 and 172,use the measurement data to determine a status of the musculoskeletalsystem, and provide a workflow to support improvement of themusculoskeletal system. Smart screws 170 and 172 can be configured toprovide therapy to bone 176 such as healing a fracture with anultrasonic signal.

FIG. 5B is an illustration of a plurality of smart screws with aplurality of smart washers in communication with one another inaccordance an example embodiment. A smart screw 180 having a smartwasher 182 is located in bone 188 at a first location. Smart screw 180and smart washer 182 each have a measurement system 130.

Surfaces are made transparent to show measurement systems 130. Eachmeasurement system 130 of smart screw 180 and smart washer 182 canperform different functions. Measurement system 130 of smart screw 180is screwed into bone 188. Measurement system 130 of washer 182 couplesto a surface of bone 188 such that measurement system 130 of washer 182can interface with bone 188 or an external environment in proximity tobone 188.

A smart screw 184 having a smart washer 186 is located in bone 188 at asecond location. Smart screw 184 and smart washer 186 each have ameasurement system 130. Surfaces are made transparent to showmeasurement systems 130. Each measurement system 130 of smart screw 184and smart washer 186 can perform different functions. Measurement system130 of smart screw 184 is screwed into bone 188. Measurement system 130of washer 186 couples to a surface of bone 188 such that measurementsystem 130 of washer 186 can interface with bone 188 or an externalenvironment in proximity to bone 188.

In general, each measurement system 130 can be in communication withanother measurement system 130. The communication can be two-way orone-way. In one embodiment, communication can occur through ultrasonic,radio frequency, magnetic, optical, or other signal types. Signalsoutput by each measurement system 130 can also be used to measure aparameter or to provide some form of therapy. In the example, smartwasher 182 is communicating with smart screw 184 in bone 188. Smartwasher 186 is communicating with smart screw 180. Smart washer 182 and184 are in also in communication with one another. The communicationcould be to initiate a measurement, receive measurement data, provideinformation, or provide therapy that affects bone 188. Although notshown, a computer could also be receiving and analyzing measurement dataor information from smart screw 180, smart screw 184, smart washer 182,and smart washer 186 to analyze or provide it to a patient or doctor forproviding feedback on the injury or repair.

FIG. 6A is an illustration of a smart plate 190 in accordance with anexample embodiment. A smart plate 190 has one or more measurementsystems 130. Smart plate 190 also has two or more openings. Each openingin smart plate 190 is configured to receive a smart screw. As shown, asmart screw 192 and a smart screw 194 couples through openings in smartplate 190 to fasten plate 190 to the musculoskeletal system. In oneembodiment, plate 190 distributes loading by smart screw 192 and smartscrew 194 across a surface of plate 190 thereby decreasing the loadingper unit area on the musculoskeletal system. Plate 190 also provides oneor more locations for housing measurement systems 130. In oneembodiment, plate 190 can have one or more cavities in which measurementsystems 130 are placed. Alternatively, measurements systems can becoupled to a surface of plate 190. Measurement systems 130 of plate 190can be in communication with smart screws 192 and 194, a computer, oreach other.

FIG. 6B is an illustration of plate 190 coupled to bone 196 inaccordance with an example embodiment. Plate 190 couples to a bone 196held in place by smart screw 192 at location 200 in bone 196. In oneembodiment, a washer 198 can be used in conjunction with smart screw 192to hold plate 190. Similarly, plate 190 is held in place by smart screw192 at location 202 in bone 196. Plate 190 distributes loading to bone196 over the area of plate 190 in contact with bone 196 versus the areaof washer 198 or the head of screw 194. Note the area of plate 190 issignificantly larger than washer 198 and the head of smart screw 194combined. Measurement systems 130 on plate 190 can be in communicationwith smart screws 192 and 194. Similarly, measurements systems 130 onplate 190 can be in communication with one another. A computer (notshown) can also communicate with measurement systems 130 of plate 190 orsmart screws 192 and 194. In one embodiment, measurement system 130 ofplate 190 can be providing a therapy for healing a bone as indicated byenergy wave 204.

FIG. 7A is an illustration of a handle 210 in accordance with an exampleembodiment. Handle 210 is used to rotate and torque a percutaneous screwinto the musculoskeletal system. Handle 210 includes a measurementsystem 130 configured to support a placement of a percutaneous screw.The walls of handle 210 are made transparent to show that measurementsystem 130 is within a cavity of handle 210. In one embodiment, aplurality of percutaneous screws can be placed in vertebra of the spineto hold a metal rod configured to shape and stabilize the spine. Thepercutaneous screws must be coupled to a strong dense portion of thevertebra to hold the metal rod that forcibly changes the spine shape.The percutaneous screws could loosen or pull out if not fastenedcorrectly into an area of strong bone mass. In one embodiment, handle210 is 4-10 centimeters long. In one embodiment, measurement system 130can measure the torque applied to the smart screw being installed aswell as measure other parameter related to the installation.

FIG. 7B is an illustration of a percutaneous screw 220 in accordancewith an example embodiment. Percutaneous screw 220 includes ameasurement system 130. A connector 222 is configured to couple tohandle 210 of FIG. 7A. Connector 222 can include leads from measurementsystem 130 of percutaneous screw 220 that couple to measurement system130 of handle 210 of FIG. 7A or other electronic circuitry within handle210 of FIG. 7A. Alternatively, leads from measurement system 130 ofpercutaneous screw 220 do not have to couple to handle 210. For example,leads extending into connector 222 can be antenna leads forcommunication. A shaft of percutaneous screw 210 is cannulated to housemeasurement system 130. The walls of the shaft are made transparent toshow measurement system 130.

FIG. 7C is an illustration of handle 210 coupled to percutaneous screw220 in accordance with an example embodiment. Handle 210 is rotated suchthat threads of percutaneous screw 220 drill into bone 230. Uponreaching a predetermined distance within bone 230 the drilling isstopped. In one embodiment, the predetermined distance can be measuredby one of measurement system 130 of handle 210 or measurement system 130of percutaneous screw 220. In one embodiment, prongs can be extendedfrom percutaneous screw 220 to further stabilize percutaneous screw 220within bone 230.

FIG. 7D is an illustration of handle 210 removed from percutaneous screw220 after being screwed into bone 230 in accordance with an exampleembodiment. Percutaneous screw 220 is screwed into bone 230 such thatmeasurement system 130 within percutaneous screw 220 is embedded withinbone 230. An opening 240 in bone 230 from drilling percutaneous screw220 into bone 230 exposes connector 222 within bone 230. In oneembodiment, an antenna 242 resides within connector 222 that supportscommunication to one or more devices. In the example, handle 210 is incommunication with percutaneous screw 220. Measurement system 130 ofpercutaneous screw 220 can output one or more signals for measurement ortherapy within bone 230 for measuring a parameter that can be receivedby handle 210. Similarly, measurement system 130 in handle 210 canoutput one or more signals that are configured to measure a parameter orprovide therapy to bone 230 or percutaneous screw 220.

FIG. 8 is an illustration of an orthopedic measurement system 250 inaccordance with an example embodiment. Orthopedic measurement system 250comprises a computer 252, a patch device 256, subcutaneous screw 262,and subcutaneous screw 264. Orthopedic measurement system 250 has twoway communication between computer 252, patch device 256, and one ormore batteryless devices that are implanted in the musculoskeletalsystem. The patch device 256 is configured to be placed in proximity tosubcutaneous screws 262 and 264. Patch device 256 can provide energy topower subcutaneous screws 262 and 264 to measure one or more parameters.In general, subcutaneous screws 262 and 264 have one or more sensorsconfigured to measure one or more parameters. Subcutaneous screws 262and 264 can be configured to provide therapy or support improved healthlocally or throughout the body. Subcutaneous screws 262 and 264 cantransmit measurement data to patch device 256 or computer 252. Display254 of computer 252 can display the measurement data. Computer 252 caninclude one or more computer programs that can analyze the measurementdata, utilize the measurement data in a process, procedure, workflow, orreview, and further transmit the measurement data or results to apatient, doctor, surgeon, or other medical staff to support patienthealth.

In the example, a subcutaneous screw 262 and a subcutaneous screw 264are coupled to the musculoskeletal system. Subcutaneous screw 262 isplaced within femur 258 and subcutaneous screw 264 is placed withintibia 260. In one embodiment, femur 258 is drilled and tapped such thatsubcutaneous screw 262 is placed in a first predetermined location infemur 258. Similarly, tibia 260 is drilled and tapped such thatsubcutaneous screw 264 is placed in a second predetermined location intibia 260. Subcutaneous screws 262 and 264 are screwed into theircorresponding openings in femur 258 and tibia 260 and can be placedtemporarily or permanently.

As mentioned previously patch device 256 is placed in proximity tosubcutaneous screws 262 and 264. In the example, patch device 256 canhave a medical grade adhesive that couples patch device 256 to a skin ofthe patient. The medical grade adhesive will make patch device 256adhere to the skin under active conditions but can be removed. Ideally,the placement of patch device 256 is the shortest distance betweenscrews 262 and 264 that maximizes energy transfer and communication. Inone embodiment, subcutaneous screws 262 and 264 do not have a powersource. Energy is provided by patch device 256 and stored onsubcutaneous screws 262 until a predetermined energy threshold is metthat supports operation of subcutaneous screw 262 or 264 for apredetermined time period. In one embodiment, the predetermined timeperiod corresponds to having sufficient energy to take measurementsusing the one or more sensors and to transmit the measurement data topatch device 256.

In one embodiment, patch device 256, subcutaneous screw 262, andsubcutaneous screw 264 include a position measurement system or trackingsystem. In the example, the position measurement system or trackingsystem is an IMU (inertial measurement unit). The position measurementsystem can also be a GPS chip, an acoustical ranging device, opticaldevices, inertial devices, magnetometers, inclinometers, or MEMsdevices. In general, subcutaneous screws 262 and 264 couple topredetermined locations of the musculoskeletal system. In oneembodiment, screws 262 and 264 couple to bones of the musculoskeletalsystem that move relative to one another such that screws 262 and 264track movement or position. In the example, subcutaneous screws 262 and264 are respectively implanted in femur 258 and tibia 260 during a totalknee arthroplasty in predetermined locations. The IMU within each screwcan be used to measure movement and rotation of femur 258 and tibia 260.The measurement data from the IMU of each screw can be used to determinerange of motion, joint alignment, and gait mechanics with the prostheticknee joint installed. The measurement data can further be used todetermine a regimen that optimizes user performance of the prostheticknee joint to reduce rehabilitation time or allow increased activity ormobility. Examples of other applications for subcutaneous screws 262 and264 are the use of cameras, optical sensors, or light emitting diodes tomonitor regions near the device placement. Similarly, the sensors canview synovial fluid near a joint of the musculoskeletal system tomonitor infection via color or turbidity. Sensors to monitor pH ortemperature can also be used to indicate unwanted activity in or nearthe joint. Sensors to detect micromotion of a prosthetic component tofemur 258 or tibia 260 can indicate stability of the adhesive holding aprosthetic component to bone. Subcutaneous screws 262 or 264 can be usedto provide therapy for improving the musculoskeletal system, healing afracture, or measuring bone density. Thus, the use of orthopedicmeasurement system 250 can provide substantial benefits by generatingquantitative measurement data related to the musculoskeletal system.

FIG. 9 is an illustration of communication paths of an orthopedicmeasurement system 298 in accordance with an example embodiment. Ingeneral, measurement system 298 is coupled to the musculoskeletalsystem. Measurement system 298 can be used on the knee joint, shoulderjoint, hip, spine, ankle, wrist, fingers, toes, elbow joint, skull, andgenerally bone. In one embodiment, measurement system 298 is used toassess position and movement of the musculoskeletal system. In oneembodiment, measurement system 298 can include one or more sensors toprovide measurement data or provide therapeutic benefit. The physicalparameter or parameters of interest that can be incorporated intomeasurement system 298 are temperature, blood oxygenation, pressure,sound, pH, SaO2, humidity, barometric pressure, height, length, width,tilt/slope, position, orientation, load magnitude, force, pressure,displacement, density, viscosity, light, color, sound, optical, vascularflow, visual recognition, alignment, rotation, inertial sensing,turbidity, strain, angular deformity, vibration, torque, elasticity,motion, acceleration, infection detection, pain inhibition, magnetic,gyroscopic, infrared, chemical sensing, biological sensing, and energyharvesting to name but a few. Often, two or more measured parameters areused in conjunction with another to perform a clinical assessment. Datacollection of measurement data from measurement system 298 can be usedby computer 278 or provided to a database for further analysis. Agraphical user interface can support assimilation of measurement data.The measurement data can be periodically measured and transmitted to acomputer for further processing.

Orthopedic measurement system 298 comprises a computer 278, device 282,device 284, screw 274, and screw 276. Although the example shows twoscrews 274 and 276, measurement system 298 can comprise more than twoscrews and more than two devices. In one embodiment, device 282, device284, screw 274, and screw 276 have similar or identical electroniccircuitry. In one embodiment, device 282 and device 284 are configuredto provide power to respectively to screw 274 and screw 276. In oneembodiment, a single device can provide power to multiple screws.Alternatively, multiple devices can be placed in a manner to providepower to a single screw. In general, an energy wave received by screw274 or screw 276 is converted to a DC voltage to power the electroniccircuitry therein. Using multiple devices increases the speed ofcharging and supports charging even as the orientation of themusculoskeletal system changes. For example, positioning of a device canchange as the musculoskeletal system is moved through a range of motion.In one embodiment, the energy transmitted from device 282 or device 284is a radio frequency signal of a predetermined frequency or frequencies.Any radio frequency signal within the predetermined frequency orfrequencies received by screw 274 or screw 276 is converted from analternating voltage to a DC voltage to power internal circuitry withinscrew 274 or screw 276. The transmitted radio frequency signal can alsoprovide information that is removed from the radio frequency signalprior to the energy being harvested. The screw includes at least oneantenna configured to receive the radio frequency signal and start theharvesting process.

In one embodiment, devices 282 and 284 can be used pre-operatively andpost-operatively. In one embodiment, measurement system 298 does notrequire a screw such as screws 274 and 276. Devices 282 and 284 can becoupled directly to the skin or held in place by a brace or wrap. Ingeneral, devices 282 and 284 include a position tracking device tomonitor movement, position, and trajectory of each device. Couplingdevices 282 and 284 to a first bone and a second bone of amusculoskeletal system supports tracking movement of the first bonerelative to the second bone. In one embodiment, devices 282 each includean IMU (inertial measurement unit). Devices 282 and 284 can also includeone or more sensors configured to measure one or more parameters. Thesensors can also include devices that provide therapy, healing, supportrehabilitation, or pain mitigation. Devices 282 and 284 includeelectronic circuitry 310, an enclosure, and a power source disclosedherein below. For example, a knee brace or wrap can include devices 282and 284. The knee brace or wrap is configured to hold devices 282 and284 in predetermined locations. In one embodiment, the knee brace isconfigured to couple device 282 to femur 270 and the knee brace isconfigured to couple device 284 to tibia 272. Devices 282 and 284 areconfigured to communicate with computer 278. Devices 282 and 284 cancommunicate directly or indirectly through a router, network, or meshnetwork. Devices 282 and 284 can harvest energy from radio frequencysignals they receive. In one embodiment, devices 282 and 284 use theharvested energy to charge a power source or battery within devices 282and 284 thereby allowing them to operate continuously generatingmeasurement data. Devices 282 and 284 are configured to providemeasurement data or information to computer 278. Computer 278 caninclude software that analyzes the measurement data from devices 282 and284 to measure gait mechanics that include stride, cadence, activity,and steps. Computer 278 can further include a program that uses themeasurement data for a kinetic assessment that includes balance,stability, rotation, graft adherence, graft failure proprioception,range of motion, or muscle strength. Wearing the knee brace prior to anoperation can provide patient data that provides information related topain, activity level, range of motion, and other factors that providesknowledge on the issues the patient is having and how to address aprosthetic component installation that supports a satisfactory patientoutcome. A knee brace having devices 282 and 284 also supportsrehabilitation and determination when the knee joint is healed aftersurgery. Devices 282 and 284 can include sensors, camera, or opticaldevices to monitor a surgical wound after a prosthetic knee joint isimplanted. Devices 282 and 284 can also support pain mitigation tofacilitate exercise and use of the knee joint. In one embodiment,computer 278 can be a cell phone, tablet, or small device that includesan app. Devices 282 and 284 provide measurement data to the app in thecell phone, tablet, or small device that monitors movement, exercise, orother sensor information. The information related to rehabilitation canbe provided to a doctor or staff for review. Data analytics using themeasurement data from devices 282 and 284 can be used to modify atherapy to improve results or indicate that the knee joint is fullyhealed and normal activity can be resumed. Recorded movement or motioncan be displayed on a display or compared with prior measurement data toindicate progress. Milestones or issues can be detected using themeasurement data and sent to the patient or to a doctor and staff. Thedoctor or staff can contact the patient if an issue requires a change ina workflow. Measurement data from devices 282 and 284 can be used todetermine when an office visit occurs. Although a knee joint was used asan example, devices 282 and 284 can be coupled to monitor movement ofany two bones of the musculoskeletal systems such as spine, hip,shoulder, elbow, ankle, wrist, hand, toes. The measurement data fromdevices 282 and 284 can be of an individual bone or two bones inrelation to one another.

In one embodiment, screws 274 and 276 can be implanted during a kneearthroplasty or during a separate surgery. The prosthetic components ofthe prosthetic knee joint are not shown but femur 270 and tibia 272 areexposed during the installation so it is a simple task to install screws274 and 276 at this time. A cavity 300 is drilled into femur 270 of themusculoskeletal system. Cavity 300 is tapped having threading similar toscrew 274. Screw 274 is then screwed within cavity 300. Differentmethodologies can be deployed to ensure that screw 274 does not loosen.The threading can be an interference fit that tightens as screw 274 isscrewed within the cavity. Alternatively, an adhesive could be appliedto the threading of screw 274 that bonds the threads of screw 274 tofemur 270. The strength of the bond can be such that screw 274 can beremoved when required. A similar process is also performed for screw 276in tibia 272. The predetermined locations of screws 274 and 276respectively in femur 270 and tibia 272 are provided to and stored incomputer 278. In one embodiment, the precise depth and location ofscrews 274 and 276 are used in accurately monitoring range of motion,alignment, rotation, anterior-posterior movement, and other positionalinformation to assess knee mechanics.

Devices 282 and 284 are respectively placed near screws 274 and 276.They can be held in place by adhesive on devices 282 and 285 aspreviously disclosed or by being placed in a wrap that couples to themusculoskeletal system in a manner that supports placement near screws274 and 276. Devices 282 and 285 can each have one or more sensors orone or more devices for generating measurement data or providing atherapeutic benefit. In the example, due to proximity, screw 274 isprimarily receiving energy from device 282. Similarly, due to proximity,screw 276 is primarily receiving energy from device 284. Once energized,screws 274 and 276 can provide measurement data continuously as long asdevices 282 and 284 are transmitting a radio frequency signal thatenergizes screws 274 and 276. In the example, the radio frequency signaltransmitted from devices 282 and 284 is typically less than 1 gigahertz.Operating below 1 gigahertz allows sufficient penetration through skinand fluids of the musculoskeletal system to be received in an efficientmanner to energize a screw. As previously mentioned, several devices canbe used in parallel to transmit to a single screw if the location of thescrew is such that the energy is not received at levels that energizesthe device to maintain operation. For example, several devices can beplaced in a wrap to focus the radio frequency transmission to a singlescrew. The combined radio frequency transmission can increase the energyreceived by the antenna of the screw for harvesting.

In one embodiment, the electronic circuitry in a screw such as screws274 and 276 are identical or substantially equal to the electroniccircuitry in devices 282 and 284. This supports reducing cost of thescrews or devices by minimizing differences that support repurposing theconcept for different applications in the medical space, industrialspace, or consumer space that supports increased volume. Thus, devices282 and 284 have one or more sensors coupled to the electroniccircuitry. Devices 282 and 284 can also be configured to generatemeasurement data and transmit the measurement data to computer 278.Devices 282 and 284 include a battery for energy storage. In oneembodiment, the battery of the device is a flexible planar structurethat supports two way communication, quantitative measurement, andprovides energy to a screw to perform a measurement process. Theflexible planar structure of the battery supports a form factor as apatch that can couple to a non-planar surface. The battery can be arechargeable device. For example, devices 282 and 284 can receive energyfrom a radio frequency transmission from computer 278 because devices282 and 284 have the same electronic circuitry as screws 274 and 276.The harvested energy by devices 282 and 284 can be used to recharge thebattery or to supplement the power expended during operation of screw274 and 276.

Each component of orthopedic measurement system 298 has two waycommunication electronic circuitry. In one embodiment, communication canoccur over a single frequency band. Alternatively, two way communicationcan occur over two or more different frequencies. In one embodiment, ahandshake can occur between two devices or two or more devices oforthopedic measurement system 298 before communication are established.In one embodiment, a screw such as screw 274 or screw 276 will receive aradio frequency signal for a predetermined time before beginning ahandshake with another device such as computer 278, device 282, ordevice 284. Energy harvesting occurs during the predetermined time thatallows operation of the screw for the handshake, sensor measurement, andtransmission of measurement data from the screw.

In the example, device 282 is in two way communication with screw 274 asindicated by double headed arrow 286. Device 282 is coupled to the skinoverlying femur 270 in proximity to screw 274. In one embodiment, device282 can have an antenna focused towards screw 274. Alternatively, device282 can have an antenna that is omni-directional to supportcommunication in all directions. Screw 274 is configured to takemeasurement data and transmit the measurement data to device 282. Device282 can also be configured to generate measurement data from sensors ondevice 282. The measurement data from screw 274 or device 282 can bestored in memory on device 282 or transmitted to another device. In oneembodiment, device 282 transmits the measurement data to computer 278for review and analysis in real-time as indicated by double headed arrow288. In one embodiment, screw 274 can have two way communicationdirectly to computer 278 as indicated by double headed arrow 290.Similarly, device 282 can also be in two way communication directly tocomputer 278 at the same time as screw 274.

In the example, device 284 is in two way communication with screw 276 asindicated by double headed arrow 292. Device 284 is coupled to the skinoverlying tibia 272 in proximity to screw 276. In one embodiment, device284 can have an antenna focused towards screw 276. Alternatively, device284 can have an antenna that is omni-directional to supportcommunication in all directions. Screw 276 is configured to takemeasurement data and transmit the measurement data to device 284. Device284 can also be configured to generate measurement data from sensors ondevice 284. The measurement data from screw 276 or device 284 can bestored in memory on device 284 or transmitted to another device. In oneembodiment, device 284 transmits the measurement data to computer 278for review and analysis in real-time as indicated by double headed arrow294. In one embodiment, screw 276 can have two way communicationdirectly to computer 278 as indicated by double headed arrow 296.Similarly, device 284 can also be in two way communication directly tocomputer 278 at the same time as screw 276. Thus, there are asubstantial number of communication paths that can be set up inorthopedic measurement system 298 because each device of the system hastwo way communication capability. In one embodiment, orthopedicmeasurement system 298 can be daisy chained to simplify the movement ofmeasurement data. For example, device 282 receives or stores measurementdata from screw 274 and device 282 as previously stated. Device 282transmits the measurement data to device 284 as indicated by arrow 302.Device 284 also receives or stores measurement data from screw 276 anddevice 284. Device 284 than transmits measurement data related to device282, device 284, screw 274, and screw 276 to computer 278 for displayingand analyzing the measurement data.

FIG. 10 is an illustration of electronic circuitry 310 for two waycommunication configured to receive energy to support internal powering,or configured to transmit energy to power another device in accordancewith an example embodiment. In general, a system can be formed with aslittle as two devices having electronic circuitry 310 that cancommunicate with each other. Electron circuitry 310 can be placed in thescrews or devices of FIGS. 1-9. A battery or power source can be coupledto electronic circuitry 310 to provide power to electronic circuitry.Alternatively, electronic circuitry can be operated without a battery orpower source. The screw or device without a power source can be poweredby a signal. In one embodiment, the signal is then harvested bycircuitry within electronic circuitry 310 to power the screw or device.The screw or device with or without a battery or power source caninclude one or more sensors or therapeutic circuitry that operates inreal-time while transmitting and receiving information. Electroniccircuitry 310 can be used in patch device 256, subcutaneous screw 262,and subcutaneous screw 264 of FIG. 8. Similarly, electronic circuitry310 can be used in device 282, device 284, screw 274, and screw 276 ofFIG. 9. In both examples, systems 250 and 298 respectively of FIG. 8 andFIG. 9 are used to generate measurement data directly within the bodyand more specifically related to the musculoskeletal system. Systemsusing electronic circuitry 310 are not limited to medical devices aswill be disclosed herein below.

Electronic circuitry 310 comprises a dual band antenna 312, a frequencyband modulation split circuit 314, a radio frequency to DC radiorectifier circuit 316, an energy storage device 318, a DC-DC converter320, a transceiver 322, and an IMU 330. Electronic circuitry 310 caninclude control logic, memory, and software programming to support aprocess or function that a device or screw performs. In one embodiment,transceiver and control circuit 322 can comprise one or more ofBluetooth, Bluetooth Low Energy (BLE), Zigbee, Wimax, Wifi, or othercommunication circuitry. Electronic circuitry 310 can further includesensors 332 to monitor or provide measurement data. Sensors 332 caninclude one or more devices configured to provide a therapy or improvehealth. A dual band antenna 312 can comprise two separate antennas eachoptimized for a specific frequency. In general, electronic circuitry 310can operate at two or more frequencies. In the example, electroniccircuitry 310 operates at two frequencies. One of the frequencies isbelow 1 gigahertz to support efficient transfer of energy via radiofrequency below the skin. In the example, one antenna can be tuned to afrequency below 1 gigahertz in the ISM band. The second antenna can betuned to a frequency depending on the application. Although the lowerfrequency (1 gigahertz) will be more efficient in energy transfer bothfrequencies can be used to harvest energy. In one embodiment, the secondantenna operates at a frequency associated with an I.E.E.E. standardthat has wide acceptance and supports wireless communication such asZigbee, WiFi, Bluetooth, Bluetooth Low Energy (BLE), or WiMax but is notlimited to such. These standards support communication and thetransmission of data. Some of these standards support low power andmedium to short range transmission. In one embodiment, a batterylessdevice using electronic circuitry 310 will use a Bluetooth Low Energy(BLE) transceiver. A BLE transceiver is configured to communicate withany Bluetooth device. The BLE transceiver operates at reduced power thatreduces the requirements of energy storage device 318 thereby reducingenergy storage requirements to operate electronic circuitry 310 andsupports a smaller form factor. In one embodiment, a device having asecondary power source such as a battery can use a standard Bluetoothtransceiver. Bluetooth operates at 2.4 gigahertz and supports high speeddata transfer within a 10M radius.

Dual band antenna 312 receives a radio frequency signal. Frequency bandmodulation split circuit 314 couples to dual band antenna 312 andremoves information that is carried on the radio frequency signal. Inone embodiment, the received radio frequency signal is in the ISM bandat 915 megahertz. The information is provided to transceiver and controlcircuit 322. Transceiver and control circuit 322 is configured to useinformation from the radio frequency signal, control a measurementprocess, and transmit measurement data. The radio frequency signal (withinformation removed) is provided by frequency band modulation splitcircuit 314 to radio frequency to DC radio rectifier circuit 316. Ingeneral, the radio frequency signal is a low power signal. In oneembodiment of radio frequency to DC radio rectifier circuit 316, aninput matching circuit couples to dual band antenna 312 to efficientlyconvert an electromagnetic signal to an electrical signal. Theelectrical signal is then coupled to a rectifier circuit that produces aDC voltage.

Radio frequency to DC radio rectifier circuit 316 couples to energystorage device 318. As it name implies, energy storage device 318 storesenergy that will be used to enable electronic circuitry 310. There aremany types of energy storage devices that can be used such as aninductor, a battery, a capacitor, magnetic storage, electrochemicalstorage, or chemical storage to name but a few. In the example, energyfrom radio frequency to DC radio rectifier circuit 316 is stored on asuper capacitor. Energy storage device 318 is configured to storesufficient energy to operate electronic circuitry 310 for apredetermined time period after the radio frequency signal is no longerreceived. In one embodiment, energy storage device 318 charges forapproximately 10 seconds before electronic circuitry 310 is enabled. Inone embodiment, the charge in energy storage device 318 is sufficient togenerate measurement data and transmit the measurement data to anotherdevice.

Energy storage device 318 couples to DC-DC converter 320. DC-DCconverter 320 is configured to generate one or more voltages to powerelectronic circuitry 310. Typically, the voltage on energy storagedevice 318 is lower than needed. DC-DC converter 320 multiplies thevoltage to a usable value for electronic circuitry 310. In oneembodiment, DC-DC converter generates one or more voltages from 0.9volts to 3.6 volts. DC-DC converter 320 couples to transceiver andcontrol circuit 322 to power a measurement process. In one embodiment,transceiver and control circuit 322 is not enabled until energy storagedevice 318 stores a predetermined amount of energy. Once enabled,transceiver and control circuit 322 controls a measurement process andis configured to transmit measurement data. Transceiver and controlcircuit 322 can include memory. The memory can be used to storesoftware, calibration data, measurement data, programs, workflows, orother information. IMU 330 and sensors 332 couple to transceiver andcontrol circuit 322. In one embodiment, each device having electroniccircuitry 310 will include IMU 330 as a position measurement or trackingdevice thereby monitoring position and relational positioning betweendevices. In one embodiment, IMU 330 comprises a geomagnetic sensor 324,a gyroscope sensor 326, and an accelerometer sensor 328. IMU 330 isconfigured to measure 6 degrees of freedom comprising translationmovement along the X, Y, and Z axis as well as rotational movement suchas yaw, roll, and pitch around each axis. Sensors 332 can be added tomeasure one or more parameters of interest and may differ depending onthe application of the device.

FIG. 11 is an illustration of multiple views of a device 350 inaccordance with an example embodiment. Device 350 is configured to powera batteryless device that can provide therapeutic benefit or generatemeasurement data. Device 350 includes two way communication circuitryfor sending and receiving information. A first side 352 and a secondside of 354 of the internal structure of device 350 are illustrated inFIG. 11. First side 352 is shown with an enclosure removed to illustratethe components therein and with the enclosure. Electronic circuitry 310of FIG. 10 can be viewed on first side 352 with without the enclosure.Electronic circuitry 310 is mounted to and interconnected on a printedcircuit board 356 to form an electronic system. In one embodiment,printed circuit board 356 is a multi-layer printed circuit boardconfigured to support a small form factor of device 350. Electroniccircuitry 310 and printed circuit board 356 forms a module 396 that canbe used for powered and batteryless devices in many differentapplications. The small form factor, two way communication, and radiofrequency powering supports applications for medical devices, industrialapplications, and the internet of things where small size and low powerare critical. Printed circuit board 356 couples to a flexible printedcircuit board 358. A battery 360 can couple to flexible printed circuitboard 358 to provide power to electronic circuitry 310. A non-powereddevice would be identical but without battery 360. In one embodiment,battery 360 is a planar structure that can flex to conform to anon-planar surface. In one embodiment, battery 360 is a rechargeablebattery. Battery 360 couples to electronic circuitry 310 throughflexible printed circuit board 358.

Referring to second side 354 of device 350, it can be seen that flexibleprinted circuit board 358 comprises an approximately oval shape. Astripe 368 of flexible printed circuit board 358 couples through theoval shape. In one embodiment, the majority of printed circuit board 356and battery 360 is mounted on stripe 368 internal to the oval shape offlexible printed circuit board 358. In one embodiment, printed circuitboard 356 is configured to bridge from flexible printed circuit board358 to stripe 368 of flexible printed circuit board 358. A first antenna362 is formed on the oval shape portion of flexible printed circuitboard 358. In one embodiment, first antenna 362 is an antenna fortransmitting a frequency less than 1 gigahertz. A second antenna 364 isformed on printed circuit board 356. In the example, second antenna 364is for a 2.4 gigahertz Bluetooth signal. First side 352 is shown overmolded with a flexible substance that forms the enclosure thathermetically seals electronic circuitry 310, printed circuit board 356,battery 360, and flexible printed circuit board 358. For example, theflexible substance for forming the enclosure can be a polymer or asilicone.

A package 366 also called the enclosure is formed over electroniccircuitry 310, printed circuit board 356, flexible printed circuit board358, and battery 360 on first side 352 and second side 354. First sideof package 366 illustrates battery 360 and electronic circuitry 310being covered respectively by area 365 and area 367 of package 366. Inone embodiment, package 366 hermetically seals the electronic circuitrythe battery from an external environment. In one embodiment, package 366is formed by over-molding a flexible material on the components. In oneembodiment, the flexible material is a silicone that remains flexible sodevice 350 will conform to a non-planar surface. Not shown, is secondside 354 that is also over-molded with the flexible material such thatall components of device 350 are sealed from the external environment bypackage 366.

Device 350 is a wearable device having two way communication, operableat two or more different frequencies, has the capability of providingradio frequency energy to a batteryless device, can receive radiofrequency energy to charge battery 360, and is conformable to be placedon a non-planar surface. In the example, device 350 is a medical deviceconfigured to couple to the musculoskeletal system to monitor position,relative position, measure one or more parameters with one or moresensors, or to support healing, therapy, or rehabilitation. In oneembodiment, device 350 can provide approximately 10 milliamps of currentto charge a device or screw. The size of device 350 is about the size ofa band aid. For example, it can be attached to the skin. In oneembodiment, device 350 has an adhesive system. The adhesive system isapplied to second side 354 of device 350. The adhesive system has acover that is removed prior to using device 350. Removing the coverexposes an adhesive layer of a medical grade adhesive. In oneembodiment, the adhesive layer couples device 350 to the skin of apatient. Device 350 can flex and change shape as the skin is changescontour under normal use. The adhesive layer supports holding device 350to the skin but also allows removal of device 350 similar to a bandage.In one embodiment, an area of device 350 is less than 25 millimeters by47.5 millimeters. Device 350 has a thickness of less than 4 millimeters.Device 350 is hermetically sealed so it can operate in a wet environmentand can be removed at any time. Alternatively, device 350 or multiplesof device 350 can be placed in a band that can be coupled to an object.For example, the band can be a wrap having several of devices 350 withinthe band that is placed around the knee region to locate the devices ona surface of the leg at predetermined locations.

FIG. 12 is an illustration a partial view of a subcutaneous screw 380 inaccordance with an example embodiment. Subcutaneous screw 380 is adevice having no internal power source such as a battery and requirespower from another source prior to being enabled. A threaded section ofsubcutaneous screw 380 is removed to illustrate electronic circuitry 310therein. Subcutaneous screw 380 comprises a screw head 384, a screw body386, module 396, a first antenna, and a second antenna. Module 396 isdisclosed in FIG. 11 and comprises printed circuit board 356 andelectronic circuitry 310 shown in FIG. 10. The electronic circuitry 310is interconnected on a printed circuit board 356 to allow subcutaneous380 to receive one or more radio frequency signals that is converted toa DC voltage that powers subcutaneous screw 380. In one embodiment, thefirst and second antennas are formed on printed circuit board 356. Inone embodiment, modules 356 in FIG. 10 and FIG. 11 can have differentsensors configured to measure different parameters. Subcutaneous screw380 tracks position and movement, can measure one or more parametersusing one or more sensors, and can perform two way communication withanother device. In one embodiment, subcutaneous screw 380 receives powerfrom a device such as device 350 of FIG. 11 that can be placed inproximity to subcutaneous screw 80.

In one embodiment, screw head 384 comprises metal while screw body 386comprises a polymer material. Screw body 386 has a cavity 388 in whichelectronic circuitry 310 and printed circuit board 356 is retained. Inone embodiment, a potting material placed in cavity 388 can retain andhold the printed circuit board 356 in place to prevent movement. Screwbody 386 is transmissive to radio frequency signals thereby allowing twoway communication. Conversely, the metal of screw head 384 is anelectrically conductive material. In one embodiment, screw head 384 iscoupled to the ground of electronic circuitry 310, a terminal of thefirst antenna and a terminal of the second antenna. Screw head 384 cancouple to screw body by many different methods. For example, screw head384 can be held by adhesive to screw body 386. Alternatively, screw head384 can be mechanically fastened to screw body 386 by threads orfastening structure.

Referring briefly to FIGS. 1-7, different types of devices are shownthat include two way communication, one or more sensors, or one or moredevices to provide therapy, improve health, or support rehabilitation.The devices of FIGS. 1-7 can include electronic circuitry 310, printedcircuit board 382, the first antenna, and the second antenna as shown inFIG. 12. In the example, the first and second antennas are formed onprinted circuit board 356. In particular, different types of screws forthe musculoskeletal system are proposed for generating measurement dataand two way communication. Some of the screws have cavities in the bodyof the screw in which module 356, the first antenna, and the secondantenna can be placed. Alternatively, some embodiments show module 396,the first antenna, and the second antenna being placed in a washer orthe head of the screw. It should be noted that the first antenna and thesecond antenna need to be housed in a material transmissive to radiofrequency signals. A portion of the screws or devices of FIGS. 1-7comprise a conductive material to be a ground for electronic circuitry310, a terminal of the first antenna, and a terminal of the secondantenna.

FIG. 13 is an illustration of a screw housing 392 in accordance with anexample embodiment. Screw housing 392 is the complete housing for screw380 of FIG. 12. Screw head 384 comprises an electrically conductivematerial and couples to electronic circuitry 310, the first antenna, andthe second antenna of FIG. 12. Screw body 386 comprises anon-electrically conductive material (such as plastic or a polymer) andincludes a threaded region 390 and a tip 394. In one embodiment,subcutaneous screw 380 can have a length of 39.5 millimeters and anoutside diameter of 11 millimeters. In one embodiment, cavity 388 has adiameter of 7 millimeters and length of 28.4 millimeters in screw body386. Screw head 384 couples to screw body 386 hermetically sealingcavity 388. In one embodiment, a bone of the musculoskeletal system isdrilled and tapped having corresponding threads as screw body 386. Inthe example, an Allen headed wrench is coupled to screw head 384 torotate screw body 386 into the drilled and tapped bone. In oneembodiment, screw housing 392 can be removed from the musculoskeletalsystem in a minimally invasive procedure.

FIG. 14 is an illustration of a partial screw 400 in accordance with anexample embodiment. Partial screw 400 includes a screw body 402comprising a first half and a second half. In one embodiment, screw body402 when coupled together has a cavity for receiving module 356 and coilantenna 402. Screw body 402 comprises a non-electrically conductivematerial such as a plastic or polymer that is transmissive to radiofrequency signals. Screw body 402 further includes a threaded section404 configured to couple to the musculoskeletal system for placement ofpartial screw 400. Not shown is a screw head of partial screw 400. Thescrew head comprises couples to screw body 402 by adhesive, mechanicalcoupling, welding, or both. The screw head is an electrically conductivematerial that is used as a ground for electronic circuitry 310, printedcircuit board 356, coil antenna 402, and a second antenna.Alternatively, a tip can be coupled to screw body 402. The tip cancomprise an electrically conductive material that is used as a groundfor electronic circuitry 310, printed circuit board 356, coil antenna402, and a second antenna.

In one embodiment, the interior cavity of screw body 402 is cylindrical.The cylindrical cavity is configured to fit and retain coil antenna 402.Coil antenna 402 is used to improve the energy transfer to partial screw400. In one embodiment, coil antenna 402 is optimized for a firstfrequency operating below 1 gigahertz that is used to penetrate skin andfluids of a patient when partial screw 400 is coupled within a bone. Ithas been shown that coil antenna 402 is capable of generating 10milli-amperes of current when harvesting a radio frequency signal lessthan 1 gigahertz using a device such as device 350 of FIG. 11 placed onthe skin in proximity to partial screw 400. The current is sufficient torapidly charge and enable module 396 in 10 seconds or less for providingposition or motion data and measuring one or more parameters. Theharvested current will also enable module 396 to take continuousmeasurements and transmit measurement data. In one embodiment, thesecond antenna is formed on printed circuit board 356 to supportBluetooth communication.

FIG. 15A is an exploded view of device 350 with a plurality of sensors412 configured to measure one or more parameters in accordance with anexample embodiment. Device 350 is shown from first side 352 perspective.Device 350 comprises module 396, flexible printed circuit board 358, andbattery 360. In one embodiment, a plurality of sensors 412 couple toflexible printed circuit board 358. Alternatively, sensors 412 can bedevices for providing therapy, health improvement, or rehabilitation.Interconnect on flexible printed circuit board 358 couples plurality ofsensors 412 to module 396. Package 366 hermetically seals module 396,battery 360, and flexible printed circuit board 358 from an externalenvironment. In one embodiment, plurality of sensors 412 are exposed tothe external environment for taking measurements. An adhesive system 410couples to package 366 on the second side that is not shown. In oneembodiment, adhesive system 410 is a medical grade film adhesive andcover configured to adhere to skin or other objects. Adhesive system 410has a removable cover that protects the adhesive until device 350 isused. Although not shown, package 366 forms an enclosure completelyaround module 396, battery 360, and flexible printed circuit board 358.Adhesive system 410 couples to the underside of package 366. Adhesivesystem 410 can be a double sided adhesive to couple to the underside ofpackage 366 or be coupled to package 366 with an adhesive. In theexample, plurality of sensors 412 is exposed to the environment. Package366 is formed around plurality of sensors 412 such that a surface ofeach sensor 412 is exposed for measurement. Similarly, adhesive system410 has cut outs that leave the surface of plurality of sensors 412exposed.

FIG. 15B is an exploded view of device 350 with a plurality of sensors412 configured to measure one or more parameters in accordance with anexample embodiment. Device 350 is shown from the second side 354perspective corresponding to an underside of package 366. Adhesivesystem 410 couples to package 366. In one embodiment, adhesive system410 is a double-sided film adhesive having one side coupled to theunderside of package 366. The exposed side of the double sided filmadhesive can have a removable cover that protects the adhesive untildevice 350 needs to be attached to a surface. As mentioned previously,package 366 will be formed around plurality of sensors 412 such that asurface or surfaces of plurality of sensors 412 is exposed to theexternal environment to which device 350 is coupled. Similarly, adhesivesystem 410 has cutouts for plurality of sensors 412 that allow exposureof plurality of sensors 412 to the external environment. In oneembodiment, package 350 on second side 354 is grooved. As shown, grooves414 are vertical and horizontal on the surface of package 366. Thegrooves support flexing of device 350 to support coupling to anon-planar surface. Coupling to a non-planar surface supports placementof plurality of sensors 412 in locations to provide accurate measurementdata.

FIG. 15C is a view of an underside of device 350 with plurality ofsensors 412 exposed for measurement to an external environment inaccordance with an example embodiment. In one embodiment, adhesivesystem 410 as shown in FIG. 15B supports coupling of device 350 to anon-planar surface. Plurality of sensors 412 can be the same sensor ordifferent sensors depending on the application. Plurality of sensors 412can also be devices configured to provide therapy, health improvement,or rehabilitation. Although plurality of sensors 412 are shown placed indifferent quadrants of a sensing surface 416 of device 350 they can belocated where needed on sensing surface 416 as dictated by theapplication. There can also be more or less sensors on device 350. Inone embodiment, device 350 is powered by an internal battery. Device 350is configured to receive and transmit information including measurementdata from plurality of sensors 412. In one embodiment, the internalbattery is a rechargeable battery that can be charged by receiving oneor more radio frequency signals. As mentioned previously, device 350 canbe capable of communication via Zigbee, Bluetooth, Bluetooth Low Energy,Wifi, Wimax or other communication standards. In the example, device 350communicates using Bluetooth. In one embodiment, the Bluetoothtransceiver in device 350 is capable of connecting to two or moreBluetooth devices. Thus, multiple devices can be providing radiofrequency energy for harvesting by device 350 for charging therechargeable energy or using the energy for operation. In general, anysignal received by the antennas by device 350 will be harvested forenergy.

In one embodiment, device 350 can be used as a wound monitor. One ormore of plurality of sensors 412 can comprise a camera. Device 350 canbe coupled to the skin of a patient to protect the wound from anexternal environment. Device 350 prevents air or contaminants fromentering between the adhesive system and the surface to which device 350is coupled. Device 350 can transmit pictures taken by the camera orcameras of the wound to a healthcare team, patient, Doctor, or Surgeonto assess the wound status. Alternatively, the pictures of the wound canbe run through a program configured to determine if the wound is nothealing property. In one embodiment, changes to the wound could bedetermined over time using pictures taken at periodic intervals. Theprogram could send an alert to appropriate people if the changes do notindicate improving or healing of the wound. Thus, the issue could beaddressed in a timely fashion to prevent a more catastrophic outcome.Other sensors but not limited to a temperature sensor, a pH sensor,humidity, pressure, or a chemical sensor can be used to further supportmonitoring the wound by providing further information related to thewound status. Further benefit can be provided by device 350 by not onlymonitoring the wound but support healing of the wound area. For example,plurality of sensors 412 can comprise photo diodes, ultra violet diodes,transducers, light emitting diodes, or photo detectors. The wound areacan be irradiated by specific frequencies of light or sound waves tosupport healing and reduce recovery time. Other types of sensors couldbe added or used to provide different therapies to support wound healingor maintenance.

In one embodiment, device 350 can be used in an electrocardiographysystem. Plurality of sensors 412 can comprise one or moreelectro-cardiogram electrodes. Electro-cardiogram electrodes detectelectrical activity generated by heart muscle depolarizations thatgenerate pulsating electrical waves that are received at the skin. Thesignal level of the pulsating electrical waves can be in the microvoltrange. In one embodiment, four or more devices 350 are used each coupledto a different location around the heart. For example, a device 350could be placed around the heart in the chest area at four locations.Alternatively, a device 350 could be placed at each extremity such asright arm, left arm, right leg, and left leg to measure the pulsatingelectrical waves. As mentioned herein above, device 350 has medicalgrade tape that will stick to the skin of a patient. Each device 350used in an electro-cardiogram can connect to a computer via Bluetooth(or other wireless methodology) and transmit the measurement data inreal-time from each location. Thus, a wireless electro-cardiogram systemcan be provided using device 350.

In one embodiment, device 350 can be adapted for photo-plethysmography.Device 350 can measure heart rate, inter-beat interval, heart-ratevariability to name a few parameters of interest. Plurality of sensors412 can comprise optical sensors, photo diodes, or light emittingdiodes. For example, the adhesive on device 350 can be used to placeplurality of sensors around a fingertip which has substantial capillarytissue. In one embodiment, light from a light emitting diode ofplurality of sensors 412 from device 350 is transmitted into the tissueof the finger. The light is either absorbed or reflected to a photodiode also of plurality of sensors 412 from device 350. In oneembodiment, the photo diode is used to determine the amount of lightreflected or absorbed. The measurement data can be transmitted viaBluetooth (or other wireless methodology) to determine the heart rate.As mentioned previously, device 350 is conformable to a non-planarsurface. Thus, device 350 can be wrapped around a finger and held inplace by the medical grade adhesive. Device 350 can then be removedafter the measurements have been completed.

FIG. 16 is an illustration of a system 450 using electronic circuitry310 configured to charge a device in accordance with an exampleembodiment. In general, a device is any battery operated componentconfigured for radio frequency communication. In one embodiment, abattery in the device should be chargeable with approximate 10milliamperes of current while in use. In other words, there would be anet gain in charge of the battery even if the device was being used. Forexample, many devices having an internal battery such as a laptopcomputer or a cell phone that requires 0.5-1.0 amperes of current tocharge may not benefit from electronic circuitry 310. Conversely, otherbattery operated devices that communicate via Bluetooth, Zigbee, orother low power communication technology are likely candidates for usingelectronic circuitry 310 of FIG. 10 or module 396 of FIG. 11 as theywill use less than 10 milliamperes of current in normal usage. As anexample, a device 474 is configured with communication circuitry such asWifi, Wimax, Bluetooth, Zigbee, or other radio frequency communicationcircuitry. As a non-limiting example or system 450, device 474 is anearpiece coupled to a cellphone 456 via Bluetooth.

System 450 is used to disclose multiple methodologies to generatesufficient current using module 396 and electronic circuitry 310 tocharge device 474. System 450 comprises a Wifi router 468, one or moreBluetooth devices, cell phone 456, and device 474. In one embodiment,device 474 is in direct communication via Bluetooth handshake to cellphone 456. Device 474 can be in use or in standby waiting to communicatewith cell phone 456. A typical use of device 474 is to watch some formof content on cell phone, device 474 is coupled to an ear of a user,audio corresponding to the content is transmitted to device 474 andconverted to audible sound on device 474 to be received by a user's ear.Alternatively, device 474 can be in standby mode and will be awakened bycell phone 456 to respond to an action such as receiving a phone call.

In a typical environment there are other local systems that may be incommunication with other devices or available for connecting to cellphone 456 or device 474. In the example, router 468 is a Wifi systemthat is a wireless local area network configured for coupling to theinternet using I.E.E.E. standard 802.11. In one embodiment, router 468transmits a Wifi signal in all different directions as indicated byradio frequency signals 470. In one embodiment, Wifi system can includebeam forming. Router 468 has spatial filtering that supports directionalsignal transmission. Router 468 is shown transmitting a stronger radiofrequency signal 472 in a direction towards device 474 than the radiofrequency signals 470 being transmitted away from device 474. Bluetoothsystem 460 represents interconnected or individual devices coupledtogether or paired with other devices for communicating over shortdistances. In one embodiment, device 474 is a Bluetooth Low Energydevice capable of coupling to two or more Bluetooth devicessimultaneously. Similarly, Wimax, Zigbee, or other networks could alsobe present where device 474 is located. As shown, device 474 can be inan environment rich in radio frequency signals.

Device 474 is adapted for harvesting radio frequency energy usingelectronic circuitry 310 or module 396. A housing 452 includeselectronic circuitry 310 that is readily adapted for use with existingbattery operated device or new battery operated wireless devices. Ingeneral, the wireless technology or technologies are chosen for thedevice such as Wimax, Wifi, Bluetooth, Bluetooth Low Energy, Zigbee, orother radio frequency communication. In the example, device 474 isconfigured to receive Bluetooth and Wifi radio signals and includesantennas coupled to electronic circuitry 310. In the example of device474 being a Bluetooth headset, device 474 comprises a speaker housing476, a stem 478 extending from speaker housing, and a housing 452.Speaker housing 476 fits and retains device 474 in the Concha of theear. The interconnection of electronic circuitry 310 is modified to fitin the cylindrical form factor of housing 452 that extends from thespeaker housing. Although housing 452 is shown fitted to stem 478 thecircuitry therein can be placed anywhere within device 474 that supportscoupling to antenna 454. In one embodiment, housing 452 of stem 478extends away from the ear such that antenna 454 is free to receive radiofrequency signals. As mentioned previously, electronic circuitry 310couples to at least one antenna and can couple to two or more antennasdepending on the radio frequencies being harvested.

The following are method steps for harvesting energy to charge a batteryin device 474 in accordance with an exemplary embodiment. The method canbe practiced with more or less than the steps shown, and is not limitedto the order of steps shown. The method steps correspond to FIG. 16 tobe practiced with the aforementioned components or any other componentssuitable for such harvesting of radio frequency energy. In a first step,device 474 is coupled for two way communication to a cell phone 456 orother device as indicated by double headed arrow 458. In one embodiment,device 474 couples uniquely to cell phone 456 using a Bluetooth handshake. The Bluetooth radio frequency signal transmitted from cell phone456 can be harvested continuously to charge the battery within device474. In a second step, device 474 can request an increase in transmitpower from cell phone 456. Cell phone 456 may not automatically supportthe request depending on its own battery status or if it is beingcharged. Increasing the transmit power to device 474 from cell phone 456can greatly extend operation of device 474 or maintain the battery ofdevice 474 at full charge.

In a third step, device 474 can request coupling to one or moreBluetooth devices of Bluetooth system 460. As mentioned previously,device 474 has the ability to connect to two or more Bluetooth devices.In one embodiment, device 474 can request coupling via Bluetooth handshake to harvest energy such that no communication occurs other than thehand shake. Bluetooth devices in proximity to device 474 that arepowered by a power supply or have a large power reserve can respond byproviding power to device 474. In one embodiment, the time period inwhich device 474 can be allowed to harvest can be a predetermined time.Alternatively, devices of Bluetooth system 460 can couple to device 474for communication purposes. If so, electronic circuitry 310 will stillharvest the energy. Multiple devices of Bluetooth system 460 coupling todevice 474 is indicated by double headed arrows 462, 464, and 466.

In a fourth step, device 474 can request coupling to Router 468. In oneembodiment, beam forming is used to send a radio frequency signal ofhigher strength to support charging the battery of device 474. In oneembodiment, device 474 can be simultaneously coupled through Bluetoothand Wifi. Router 468 may not have beam forming capability. In a fifthstep, device 474 can request an increase in transmitting power.Typically, systems are optimized to minimize the transmit power. In oneembodiment, the requirement to minimize power is over ridden by therequest from device 474 for increased transmit power. The energy fromthe radio frequency signal transmitted by router 468 is harvested tomaintain operation of device 474 and charge the battery of device 474.

As mentioned previously, device 474 can be in a radio frequency signalrich environment. In a sixth step, device 474 does not need to couplevia a hand shake to a system such as router 468 or Bluetooth system 460if the radio frequency signals are received by the one or more antennasof device 474. In one embodiment, the radio frequency signals have to beabove a predetermined power to harvest the energy. This is the casewhether connected by hand shake or receiving a radio frequency signalwithout a hand shake. In one embodiment, receiving one or more radiofrequency signals greater than 100 milliwatts (20 dBm) at thetransceiver input of electronic circuitry 310 will initiate a batterycharging process in device 474.

FIG. 17 is an exploded view of device 474 in accordance with an exampleembodiment. In general, electronic circuitry 310 of FIG. 10 and printedcircuit board 356 is shown in a form factor that fits within device 474.In the example, device 474 is an earpiece configured to couple toanother device for receiving information such as audio content through aradio frequency transmission. Device 474 is not limited to an earpiecebut can be any electronic system configured to receive radio frequencycommunication. Device 474 can be a batteryless device that is powered byenergy harvest from the radio frequency transmission. Alternatively,device 474 can be a device having energy storage such as a battery thatcan be recharged by the radio frequency transmission. In both examplesthe system should operate or be capable of recharging with a current of15 milli-amperes or less. In one embodiment, approximately 10milli-amperes can be generated for operation or charging at distances of3 feet or less.

Device 474 comprises housing 452, housing cover 480, antenna 454, supercapacitor 318, printed circuit board 356, pin holder 484, and aplurality of pins 486. Electronic circuitry 310 fits within housing 352that couples to stem 478 of device 474. Speaker housing 476 is designedto couple to an ear and provide audio to a user. In the example, speakerhousing 476 houses a speaker and a rechargeable battery. Stem 478 ofdevice 474 includes interconnect coupling the speaker and rechargeablebattery to electronic circuitry 310. As disclosed in FIG. 10, printedcircuit board 356 includes components for two way communication andharvesting radio frequency signals for energy. In the example, printedcircuit board 356 utilizes Bluetooth or Bluetooth low energy circuitryfor the two way communication. In the example, speaker housing 476 fitsin and is retained by the concha of the ear such that the speaker isdirected to and partially seals the ear canal. Stem 478 of device 474places antenna 454 outside the ear in position to receive radiofrequency signals. Alternatively, antenna 454 can be placed in housing452 or step 478 to provide a smaller form factor.

In one embodiment, the components for radio frequency communication andradio frequency energy harvesting are fitted in housing 452 to maintainthe form factor of stem 478 of device 474. Antenna 454 extends throughan opening in housing cover 480. In one embodiment, antenna 454 has acurved shape at a proximal end that couples around super capacitor 318.The curved shape at the proximal end of antenna 454 retains antenna 454within housing 452. Antenna 454 and super capacitor 318 couples toprinted circuit board 356. Antenna 454 provides one or more radiofrequency signals to device 474 and super capacitor 318 stores harvestedradio frequency energy for powering device 474 or charging the batterywithin device 474. A plurality of pins 486 couple to printed circuitboard 356. In one embodiment, the plurality of pins 486 are springloaded pins that can compress. A pin holder 484 holds plurality of pins486 in predetermined positions to printed circuit board 356. In oneembodiment, housing 452 is cylindrical in shape. Printed circuit board356 and pin holder 484 are circular in shape to fit within housing 452and be retained. Pins 486 extend beyond pin holder 484. In oneembodiment, a distal end of stem 478 includes interconnect padsconfigured to couple to the plurality of pins 486. In one embodiment,the interconnect pads couple to interconnect that extends through stem478 to the speaker and the rechargeable battery within device 474. Inone embodiment, housing 452 is pressed onto stem 478 of device 474.Plurality of pins 486 couple to corresponding interconnect pads withinstem 478. As mentioned previously, plurality of pins 486 can compress tomake contact to the corresponding interconnect pads under a force orpressure. Housing cover 480 couples to housing 452 to retain thecomponents within housing 452. Thus, two way communication and radiofrequency energy harvesting can be provided in a small form factorcapable of powering or recharging device 474 while being used. Thus,electronic circuitry 310 can be adapted to an existing product forharvesting energy to charge a battery or built within the existingproduct. This provides the benefit of not requiring a charging stationfor the device as it can be charged by several different wirelessmethodologies as disclosed herein above while device 474 is in use ornot in use.

FIG. 18 is an illustration of electronic circuitry 310 placed in housing452 that couples to device 474 of FIG. 17 in accordance with an exampleembodiment. Electronic circuitry 310 provides two way communication andenergy harvesting of radio frequency signals to charge a battery orpower a batteryless device. Plurality of pins 486 extend towards aproximal end of housing 452. In the example, each pin of plurality ofpins can compress and apply a force to a corresponding contact or pad instem 478 of FIG. 17. Plurality of pins 486 are held in place by pinholder 484. In one embodiment, plurality of pins 486 couple through pinholder 484 in predetermined positions. In one embodiment, pin holder 484is retained within housing 452 by one or more retaining features.Plurality of pins 486 also extend through the distal end of pin holder484 to couple to predetermined contact points or pads on printed circuitboard 356. In one embodiment, a pin of plurality of pins 486 can be bentin a right angle as shown in FIG. 18 to provide more contact surfacearea and retain the distal portion of the pin on distal side of pinholder 484. Printed circuit board 356 has components mounted thereon andinterconnect traces to electrically couple the components together asdisclosed in FIG. 10 to form electronic circuitry 310. Electroniccircuitry 310 is configured to provide two way communication and energyharvesting of radio frequency signals for powering device 474 orcharging a power source within device 474. Printed circuit board 356 hasa plurality of pads on a proximal surface that respectively couple toplurality of pins 486 extending from the distal side of pin holder 484.In one embodiment, an internal shape of housing 452 where printedcircuit board 356 is located corresponds to the shape printed circuitboard 356 to prevent movement or rotation. In the example, printedcircuit board 356 is square or rectangular in shape. Antenna 454 andsuper capacitor 318 couples to a distal side of printed circuit board356. The distal side of printed circuit board 356 includes a pluralityof pads for coupling to super capacitor 318 and antenna 454. It shouldbe noted that components of electronic circuitry 310 can be mounted onthe proximal and distal sides of printed circuit board 356. In oneembodiment, antenna 454 is curved to retain super capacitor 318 withinhousing 452. Housing cover 480 couples to the distal end of housing 452to seal electronic circuitry 310 within housing 452. Antenna 454 extendsthrough an opening in housing cover 480 and is positioned to receiveradio frequency signals. Housing 486 is coupled to stem 478 of device474 of FIG. 17 such that plurality of pins 486 couple to correspondingpads of stem 478 for coupling to the speaker and battery. Housing 486 isheld in place compressing plurality of pins 486 under a compressiveforce that supports holding antenna 454, super capacitor 318, printedcircuit board 356, pin holder 484, and plurality of pins 486 in place.

FIG. 19 is an illustration of two antennas formed on the same substratein accordance with an example embodiment. Antennae 500 comprise a firstantenna 512 and a second antenna 514. Antennae 500 is a dual bandantenna that can be used with electronic circuitry 310 to harvest radiofrequency energy at two different frequency bands. In the example, firstantenna 512 is configured to operate at a lower frequency band thansecond antenna 514. In one embodiment, first antenna 512 is configuredto operate at frequencies less than 1 gigahertz. Operating atfrequencies less than 1 gigahertz supports radio frequency penetrationthrough liquids and solids. For example, a radio frequency signaltransmitted from an external environment having a frequency less than 1gigahertz will be received by a screw embedded in the musculoskeletalsystem at a much higher signal strength than a 2.4 gigahertz signalbeing transmitted at the same power level. It has been shown that 10-15milliamperes of current can be generated by electronic circuitry 310 ofFIG. 10 within a screw or device receiving the radio frequency signal ofless than 1 gigahertz by communicating with a transmitting device placedat or near a skin surface or within 3 feet of the screw. The 10-15milliamperes of current is sufficient to power the screw having one ormore sensors for taking quantitative measurements continuously. Firstantenna 512 operates at a frequency less than 1 gigahertz such as an ISM(industrial, scientific, and medical band). Second antenna 514 operatesat a higher frequency such as 2.4 gigahertz and uses Bluetooth,Bluetooth low energy, Wifi, Zigbee, Wimax or other communicationprotocols that have been standardized for transferring data. Firstantenna 512, second antenna 514, or both can be used for energyharvesting to generate the 10-15 milliamperes.

Antennae 500 is designed to have a predetermined efficiency,predetermined gain, and form factor for use in an energy harvestingapplication for transmitting or receiving a radio frequency signal. Inthe example, first antenna 512 is configured to operate at 915 megahertzfor transmit and receive functions using the ISM band. The secondantenna 514 is configured to operate at 2.4 gigahertz using Bluetooth orBluetooth low energy. Bluetooth is for short range communication havinga maximum output power of 100 milliwatts (20 dBm) while an ISMtransmission is higher power at 1 watt. First antenna 512 is formed on afirst side 502 of antennae 500 on a dielectric substrate 506. Antenna512 comprises a conductor 508 formed in a serpentine pattern on firstside 502. Similarly, Second antenna 514 is formed on a second side 504of antennae 500 on dielectric substrate 506. Antenna 514 comprises aconductor 510 formed in a serpentine pattern of second side 504. In oneembodiment, first antenna 512 and second 514 are designed to minimizeoverlap of conductor 508 and 510 to maximize the efficiency of theantenna. It is found that overlapping conductors 508 and 510 producesinterference that affects antenna performance.

FIG. 20 is a list of specifications for antennae 500 of FIG. 19 inaccordance with an example embodiment. As mentioned previously, dualantenna 500 is formed on a polyimide dielectric substrate that isapproximately 17.63 millimeters thick. The gain of each antenna isapproximately 2.0 dBi. The efficiency was targeted for approximately 60%to ensure sufficient current could be generated to operate a batterylessdevice (e.g. 10-15 milliamperes continuous). Dual antenna 500 has asmall form factor that is approximately 25 millimeters×25 millimeters.The gap between two layer minimum is 0.4 millimeters. In one embodiment,each antenna of antennae 500 comprises a copper plated trace that isphotolithographically etched to form the serpentine shape.

FIG. 21 is an illustration of impedance tuning and frequency tuning ofantennae 500 of FIG. 19 in accordance with an example embodiment. Afirst side 502 of antennae 500 illustrates impedance tuning andfrequency tuning for 915 megahertz. Impedance tuning 530 of firstantenna 512 is achieved by adjusting the length of the slot. Frequencytuning 534 is achieved by adjusting the height of the slot. In oneembodiment, the impedance of first antenna 512 is 50 ohms. Similarly,second side 504 of antennae 500 illustrates impedance tuning andfrequency tuning for 2.4 gigahertz. Impedance tuning 532 of secondantenna 514 is achieved by adjusting the length of the slot. Frequencytuning 536 is achieved by adjusting the length of the slot as shown. Inone embodiment, the impedance of second antenna 514 is 50 ohms.

FIG. 22 is an illustration of a measurement of antenna 512 and antenna514 of FIG. 19 in accordance with an example embodiment. The measurementillustrates that antennae 500 of FIG. 19 can operate simultaneously witha high Q. The x-axis is frequency in gigahertz and the y-axis is thereturn loss. Tuning 542 is centered at approximately 2.4 gigahertz whiletuning 540 is centered at approximately 915 megahertz. As mentionedpreviously, antenna 512 and antenna 514 can be operated simultaneouslyeven though both are formed on the same substrate and operate within thesame space.

FIG. 23 is an illustration a radiation pattern for antenna 512 andantenna 514 of FIG. 19 in accordance with an example embodiment.Radiation pattern 550 corresponds to antenna 512 operating at 915megahertz. Radiation pattern 550 is an omni-directional pattern.Radiation pattern 552 corresponds to antenna 514 operating at 2.4gigahertz. Similarly, radiation pattern 552 is an omni-directionalpattern but having more directionality than radiation pattern 550. Thus,a dual antenna on a common substrate operating at two frequencies hasbeen disclosed with omni-directional radiation patterns.

FIG. 24 is a block diagram of a system 576 in accordance with an exampleembodiment. System 576 comprises two way communication between two ormore devices. A network system 560 can be wired, wireless, or both. Inone embodiment, network system includes a router for providing trafficcontrol of information being sent between devices or the internet.System 576 includes a device 562 and a device 564. Device 562 and device564 can be wired or wireless devices. Device 562 and device 564 cancommunicate through network system 560 or directly to each other.

In one embodiment, device 562 and device 564 can be configured toharvest energy from received radio frequency signals. In the example,device 564 is being used in an application that uses energy whileharvesting radio frequency signals it receives as disclosed in box 566to charge an energy source or provide power to maintain operation. Inone embodiment, device 562 is in communication with device 564. In astep 568, device 562 and device 564 handshake and set up directcommunication with identification. In a step 570, device 564 reportsbattery status to device 562. Device 564 requests power transfer foroperation or to charge an internal battery from device 562. In a step572, device 562 responds that it will transmit to support charging ofdevice 564. Device 564 increases transmit power or transmits overmultiple channels to support the power request. In a step 574, device564 receives the radio frequency signal from device 562 and provides areport back to device 562 on the signal level or charging status. Device562 can adjust the power level of the transmission based on the reportfrom device 564. It should be noted that device 564 could also bereceiving one or more radio frequency signals from network system 560 tofurther supplement powering of device 564 or charging a battery withindevice 564. The process of requesting and increasing the power of thetransmission would be similar.

FIG. 25 is a block diagram illustrating two or more channels beingtransmitted from device 562 to device 564 in accordance with an exampleembodiment. In one embodiment, device 562 can transmit and receive withtwo or more channels. Similarly, device 564 can transmit and receivewith two or more channels where each channel. In one embodiment, theenergy harvested by device 564 can be increased by transmitting fromdevice 562 through two or more channels. In the example, two channelsare transmitted to device 564. In one embodiment, device 564 requestsand handshakes with device 562. A channel 580 under an ID1 sends a radiofrequency signal 584 that is received by device 564. Device 564 harveststhe energy from radio frequency signal 584. In one embodiment, device564 requests and handshakes with device 562 a second time. A channel 582under an ID2 sends a radio frequency signal 586 that is received bydevice 564. Device 564 harvests the energy from radio frequency signal586. Thus, the amount of energy that can be harvested can be increasedby receiving radio frequency signals through multiple channels.

FIG. 26 is a block diagram of circuitry within device 562 and device 564of FIG. 24 to support energy harvesting in accordance with an exampleembodiment. In one embodiment, device 562 and device 564 can includebeam forming 590 to direct transmission of a radio frequency signalinstead. For example, device 562 or network system 560 can beam form aradio frequency signal to device 564 to increase the power of the radiofrequency signal that is received by device 564. Device 564 will thenharvest energy at a greater rate.

In one embodiment, device 562 and device 564 can include adaptive powercontrol. In the example, where device 564 is requesting coupling todevice 564 to receive a radio frequency transmission the adaptive powercontrol can be used to increase the power of transmission. In otherwords, device 564 can request that the strength of the radio frequencysignal be increased to support energy harvesting by device 564.

In one embodiment, device 562 and device 564 will have energy harvestingcapability of radio frequency signals. The energy harvesting circuitrywill convert one or more radio frequency signals to DC power using a RFto DC power converter. The RF to DC power converter will have at leastone rectification.

FIG. 27 is a block diagram 600 illustrating a horizontal and verticalantenna array controlled by a microprocessor in accordance with anexample embodiment. The antenna array can be configured to transmit orreceive. Each horizontal antenna has a radio and amplifier forindependent control. Similarly, each vertical antenna has a radio andamplifier for independent control. Thus, more than one horizontal orvertical antenna can used simultaneously to increase power output by theantennas.

Components of FIGS. 1-16 will be referred to when discussing the medicalsystem disclosed herein below for monitoring the musculoskeletal system.The description of FIGS. 1-16 are also included in any discussion ofstructure or operation herein below. The medical system comprises one ormore screws (274, 276) coupled to the musculoskeletal system, one ormore devices (282, 284), and a computer 278. Computer 278 can be anydevice configured to receive measurement data from the one or morescrews (274, 276) or the one or more devices (282, 284). In oneembodiment, a screw 274 is configured to couple a first bone of themusculoskeletal system in a predetermined location. An opening can bedrilled in a first bone of the musculoskeletal system and tapped forreceiving screw 274. The predetermined location of screw 274 can beregistered relative to the bone model of the first bone and stored incomputer 278.

Screw 274 comprises electronic circuitry 310, an IMU 330, and a dualband antenna 312. The dual band antenna comprises a first antennaconfigured to receive or transmit a signal below 1 gigahertz and asecond antenna configured to receive or transmit a signal above 1gigahertz. In one embodiment, the dual band antenna operates at 915megahertz and 2.4 gigahertz. In one embodiment, screw 274 has anon-electrically conductive body 386 and an electrically conductive cap384. In one embodiment, body 386 of screw 274 comprises a plastic orpolymer material. At least a portion of body 386 has a threaded portion390 and a tip 394. Threaded portion 390 is configured to hold screw 274in place and retain screw 274 within the first bone of themusculoskeletal system. Electrically conductive cap 384 couples to body386 of screw 274 to seal a cavity 388 housing electronic circuitry 310,IMU 330, sensors 332, dual band antenna 312, and other circuitry orcomponents. Electrically conductive cap 384 couples to the ground ofelectronic circuitry 310. IMU 330 is configured to provide informationon position, location, movement, and trajectory corresponding to ninedegrees of freedom. In one embodiment, IMU 330 comprises a geomagneticsensor 324, a gyroscope sensor 326, and an accelerometer sensor 328.Screw 274 further includes a frequency band modulation split circuit314, a radio frequency to DC radio rectifier circuit 316, energy storagedevice 318, DC-DC converter 320, sensors 332, and transceiver andcontrol circuit 322. Electronic circuitry 310 is configured to control ameasurement process and transmit measurement data. Screw 274 can be intwo way communication with one or more devices (282, 284) or one or morecomputers 278.

Sensors 332 are configured to measure one or more parameters. Sensorscan comprise a transducer, a microphone, a temperature sensor, a forcesensor, an inertial sensor, a density sensor, an optical sensor,infection detection, blood oxygen level sensor, a position measurementsystem, a tracking system, a fluid sensor, a magnetic sensor, amechanical sensor, a pressure sensor, a pH sensor, a photo sensor, apiezo sensor, a capacitive sensor, a strain gauge, a flow sensor, achemical sensor, an infrared sensor, a flow sensor or a biologicalsensor. Sensors 332 can also be a device configured to provide therapy,heal, improve health, or support rehabilitation. For example, sensors332 can emit a continuous frequency or a pulsed signal to support bonehealing.

Device 282 is configured to couple to the skin or epidermis in proximityto screw 274. In one embodiment, device 282 is configured as a patch orbandage having an adhesive system 410. Device 282 is flexible to conformand couple to complex shaped surfaces. In one embodiment, package 366 ofdevice 282 comprises silicone to support flexibility. Adhesive system410 is coupled to a surface of device 282. A cover of adhesive system410 is removed to expose an adhesive layer prior to coupling device 282to the skin. The adhesive layer is a medical grade adhesive configuredto hold device 282 to the skin. An electronic system is placed withindevice 282 that is similar to the electronic system placed within screw274. For brevity, the individual circuits of electronic circuitry 310will not be disclosed but can be reviewed in FIG. 10. A differencebetween device 282 and screw 274 is that device 282 further includes apower source. In one embodiment, the power source is battery 360.Battery 360 can be a rechargeable battery. Battery 360 is configured topower electronic circuitry 310 in device 282 but also provide power toscrew 274. Device 282 transmits a first signal at a first frequency toscrew 274. The first signal is at a frequency of 1 gigahertz or lessthat penetrates through skin and tissue. In one embodiment, the firstsignal transmitted by device 282 is at 915 megahertz in the ISM band.Screw 274 receives the first signal transmitted from device 282 andharvests energy from the first signal. In one embodiment, screw 274 doesnot have any stored energy to operate electronic circuitry 310 therein.Thus, a first step is to begin harvesting energy that is received by thefirst antenna of screw 274. The first signal is harvested by radiofrequency to DC radio rectifier circuit 316 of electronic circuitry 310in screw 274. The rectified signal is stored on energy storage device318 in screw 274. The rectified signal typically has a voltage lowerthan needed by electronic circuitry 310. DC-DC converter couples toenergy storage device 318 and generates one or more voltages to powerelectronic circuitry 310 within screw 274. In one embodiment, electroniccircuitry 310 in screw 274 is configured to be enabled when the storedenergy in energy storage device 318 in screw 274 is above apredetermined threshold. In one embodiment, energy storage device 318 inscrew 274 is a super capacitor. The stored energy above thepredetermined threshold is sufficient to power electronic circuitry 310of screw 274 for a measurement process and transmit the measurement datato device 282, another different device, another different screw, or acomputer. Device 282 can continuously send the first signal therebyallowing continuous operation of screw 274 for generating measurementdata and transmission of the measurement data. In one embodiment, thefirst signal transmitted by device 282 to screw 274 supports thegeneration of a current to charge energy storage device 318 in screw 274of 10 milliamperes or greater.

Screw 274 and device 282 each have a dual band antenna 312 configuredfor transmitting or receiving information. Screw or device 274 anddevice 282 are configured to transmit or receive information at eitherfrequency band that dual band antenna 312 is configured to operate at.In the example, a first antenna of dual band antenna 312 operates at 1gigahertz or less. A second antenna of dual band antenna 312 operates at1 gigahertz or more. As disclosed herein operation of the first antennaat 915 megahertz which is within the ISM band while the second antennais operated at 2.4 gigahertz corresponding to Bluetooth wirelessprotocol. In one embodiment, the first antenna is a coil antenna 402 asshown in FIG. 14. The second antenna is formed on or couples to printedcircuit board 356 and housed within a cavity of screw body 402 with coilantenna 402. In one embodiment, coil antenna couples around module 396.Alternatively, an antenna 500 corresponding to dual band antenna 312 foruse on a screw or device as disclosed herein can be formed on adielectric substrate 506. Antenna 500 has an antenna formed on each sideof dielectric substrate 506 thereby forming a dual band antenna. Thefirst antenna 512 is formed having a conductor 508 on a first side 502of dielectric substrate 506. The second antenna 514 is formed having aconductor 510 on a second side 504 of dielectric substrate 506. In oneembodiment, conductor 508 overlies or overlaps conductor 510 less than50 percent to reduce interference, increase efficiency, and improve aradiation pattern of antenna 500.

In one embodiment, multiple screws, multiple devices, and one or morecomputers can be in communication with one another as a medical systemconfigured to generate measurement data. The multiple screws willreceive power through one or more radio frequency signals where the oneor more radio frequency signals are harvested for energy to power themultiple screws. This is depicted in FIG. 9 where computer 278 receivesmeasurement data to display, analyze, or report about themusculoskeletal system using quantitative measurement data or supportpatient health by providing therapy, promote healing, or rehabilitate.In the example, a device 282 is in communication with screw 274 that iscoupled to a femur 270 of a leg. A device 284 is in communication withscrew 276 that is coupled to a tibia 272 of the leg. The medical systemis configured to provide quantitative measurement data related to a kneejoint or provide therapy, promote healing or rehabilitate. Device 284has electronic circuitry 310 similar to device 282 as disclosed hereinabove. Similarly, screw 276 has electronic circuitry 310 similar toscrew 274 as disclosed herein above. Device 284 has a power source likebattery 360 of FIG. 11 to support providing a radio frequency signal topower screw 276. In the example embodiment, devices 282 and 284respectively couple to the epidermis in proximity to screws 274 and 276to support efficient radio frequency signal transfer. Devices 282 and284 can include sensors 332 for generating quantitative measurement dataor one or more devices for providing therapy, healing, orrehabilitation. Exact positions of screws 274 and 276 are knownrespective to femur 270 and tibia 272 whereby movement of the knee jointcan be precisely monitored and measured by the IMU 330 in screws 274 and276. Screws 274 and 276 are zeroed relative to gravity to supportmeasurement with 9 degrees of freedom. In one embodiment, the medicalsystem is configured to measure at least one of a range of motion,rotation, or dynamic stresses related to translation of themusculoskeletal system. In one embodiment, screws 274 and 276 areconfigured for post-operative monitoring for compliance to apost-operative regimen. In one embodiment, computer 278 is a device orphone that is used in conjunction with the medical system for runningsoftware and for transmitting and receiving information from device 282,device 284, screw 274, and screw 276. In one embodiment, the medicalsystem is configured to provide an exercise regimen that can be sent tothe device or a phone. Screws 274 and 276 are configured to be activatedto monitor the exercise regimen such that the musculoskeletal systemremains within a healing zone. In one embodiment, the medical system andcomputer 278 is configured to review the measurement data from device282, device 284, screw 274, and screw 27 to evaluate post-operativeexercises, post-operative treatment, or pharmaceuticals.

Components of FIGS. 1-27 will be referred to when discussing a wirelesssystem disclosed herein below for performing a task. The description ofFIGS. 1-27 are also included in any discussion of structure or operationherein below. The wireless system 450 comprises a device 474 configuredto receive one or more radio frequency signals. In one embodiment,device 474 operates at 15 milliamperes or less. In one embodiment,device 474 operates at 10 milliamperes or less. In general, device 474is configured to harvest energy from any radio frequency signal receivedby the antenna system of device 474. Energy harvested from one or moreradio frequency signals is stored on energy storage device 318. Device474 includes some or all the electronic circuitry 310 listed in FIG. 10for energy harvesting one or more radio frequency signals and convertingthe energy to power electronic circuitry 310 to perform at least onetask. In one embodiment, device 474 can operate continuously if the oneor more radio frequency signals are continuously provided. Distance andtransmit power are important factors for device 474 to be poweredcontinuously with one or more radio frequency signals. Device 474 can beconfigured to receive and transmit in many different frequency bands andconfigured for different wireless protocols. Examples of differentcommon wireless protocols are WiFi, Bluetooth, Zigbee, WiMax, ISM, orwireless mesh networks. In general, device 474 has antenna 454. Antenna454 can be part of an antenna system capable of receiving one or moredifferent frequency bands. For example, the antenna system of disclosedin FIG. 10 is a dual band antenna 312 operating in a first frequencyband and a second frequency band. In one embodiment, antenna 454 is anantenna that operates in a frequency band below 1 gigahertz. The secondantenna of the dual band antenna 312 of device 474 can be configured foroperation in a WiFi frequency band or Bluetooth frequency band. In oneembodiment, the WiFi or Bluetooth antenna is housed within the enclosureof device 474. In one other example, dual band antenna 312 can operateto receive and transmit WiFi and Bluetooth radio frequency signals. Inone embodiment, device 474 will harvest energy from all signals receivedon the antenna system. For example, device 474 will harvest WiFi andBluetooth signals received if device 474 is configured to receive WiFisignals from WiFi router 468, Bluetooth from cell phone 456, orBluetooth from Bluetooth system 460. In the example, Bluetooth system460 is a mesh network capable of providing interconnectivity over a widearea.

A second wireless device is configured to couple to device 474. Forexample, cell phone 456 has a rechargeable battery capable of deliveringhigh current. Router 468 or Bluetooth system 460 is powered by theelectric grid and has a transmission range (e.g. signal strength)limited by regulation. Thus, the cell phone 456, router 468, orBluetooth system 460 can be the second wireless device configured topower device 474 using a radio frequency signal. In general, the secondwireless device is configured to transmit one or more radio frequencysignals to device 474. In one embodiment, cell phone 456 is configuredto transmit a radio frequency signal to device 474. The radio frequencysignal is a Bluetooth signal. Alternatively, router 468 is configured totransmit a radio frequency signal to device 474. As an example, theantenna system of device 474 is configured to receive the Bluetooth orWiFi radio frequency signal respectively from cell phone 456 or router468. In one embodiment, antenna system of device 474 receives aBluetooth signal from cell phone 456. Device 474 is configured toharvest energy from the Bluetooth signal from cell phone 456. Device 474will also harvest energy from other Bluetooth signals the antenna systemreceives. Device 474 is enabled for operation after a predeterminedamount of energy is harvested from the Bluetooth signal from cell phone456. In one embodiment, energy harvested from the Bluetooth signal fromcell phone 456 is stored on energy storage device 318 of device 474.Electronic circuitry 310 of device 474 is enabled when a predeterminedamount of energy is harvested. In one embodiment, the predeterminedamount of energy is sufficient to enable electronic circuitry 310,perform at least one task, transmit information related to the at leasttask, and finish with an orderly shutdown of electronic circuitry 310. Acommunication handshake can occur between cell phone 456 and device 474once electronic circuitry 310 within device 474 is enabled therebyestablishing communication. Cell phone 456 can continue being incommunication with device 474. Energy is harvested by device 474 as longas cell phone 456 is in communication with device 474 thereby supportingcontinuous operation of device 474.

In general, device 474 can communicate to the second wireless devicethat more power is required by device 474 to continue operation. Forexample, if the distance increases between device 474 and the secondwireless device the signal strength may need to be increased togenerated sufficient power to maintain operation. Similarly, the signalcould be blocked or reflected requiring an increase in signal strength.In one embodiment, the communication between device 474 and the secondwireless device can be a feedback path to modulate a transmit power ofthe second medical device to support continuous operation of device 474.Thus, the transmit power can be increased or decreased depending onamount of energy being harvested and the task being performed by device474. In one embodiment, harvested energy stored on energy storage device318 is monitored. Monitoring the harvested energy supports communicationon the feedback to modulate the transmit power sent by the secondwireless device. In one embodiment, the communication between device 474and the second wireless device to increase or decrease the transmitpower can include using beam forming. Beam forming increases thedirectivity of the transmit power from the second wireless device. Thetransmission is more focused at device 474 thereby increasing thetransmit power by reducing radiation in other directions.

Although device 474 does not require a power source, it may in somecircumstances be beneficial to have a local power source within device474. For example, device 474 can include a rechargeable battery. In oneembodiment, DC-DC Converter 320 of electronic circuitry 310 withindevice 474 can include the ability to charge the rechargeable batterywhile electronic circuitry 310 is enabled or when electronic circuitry310 is not communication within another device. This supports keepingdevice 474 powered in the event that the signal between device 474 andthe second wireless device weakens or is blocked for a short period oftime. The battery can sustain activity and keep electronic circuitry 310with device 474 operating. Energy harvesting by device 474 provides thebenefit of eliminating a battery charging station for device 474.

In one embodiment, device 474 has dual band antenna 312. Dual bandantenna 312 comprises two or more antennas operating at two or morefrequency bands. The two or more frequency bands are non-overlapping. Inone embodiment, dual band antenna has a first antenna that operates atfrequencies below 1 gigahertz and a second antenna that operates atfrequencies above 1 gigahertz. The lower frequency antenna supportsbetter penetration through different materials thereby improvingefficiency for radio frequency energy transfer. The second antenna cancomprise more than one antenna for the frequency bands above 1 gigahertzand can support Bluetooth, WiFi, or other communication standards fortwo way communication with device 474. The second wireless device cancomprise router 468, cell phone 456, Bluetooth system 460, or a patchdevice 256 (as shown in FIG. 8) as examples of interconnectivity todevice 474. In one embodiment, patch device 256 transmits at the firstfrequency below 1 gigahertz to device 474. In one embodiment, router468, cell phone 456, or Bluetooth system 460 can communicate to device474 through the frequency band above 1 gigahertz. In the example, powertransfer to device 474 is performed efficiently by using a lowerfrequency while communication can occur using a standard protocol. Inone embodiment, dual band antenna 312 of device 474 has a first antenna512 formed on first side of a substrate 506 and a second antenna 514formed on a second side 504 of substrate 506 thereby reducing a formfactor. The first antenna 512 and the second antenna 514 of dual bandantenna 312 of device 474 operates at different non-overlappingfrequencies. In one embodiment, a conductor 508 of first antenna 512 anda conductor 510 of the second antenna 514 overlaps each other less than50 percent to improve efficiency.

Device 474 includes a radio frequency to DC radio rectifier circuit 316,energy storage device 318, a DC-DC converter 320, and an IMU 330. DCradio rectifier circuit 316, energy storage device 318, a DC-DCconverter 320 are configured to receive, harvest, store, and convertenergy from one or more radio frequency signals coupled to device 474into one or more voltages to power transceiver and control circuit 322of electronic circuitry 322. In one embodiment, IMU 330 comprisesgeomagnetic sensor 324, gyroscope sensor 326, and accelerometer sensor328. IMU 330 is a position and trajectory tracking system having ninedegrees of freedom to determine position, location, or trajectory. Anexample of device 474 that operates with a current of 15 milliamperes isan audio device such as ear phones or ear buds used with cell phone 456.Cell phone 456 can sustain used of device 474 as an audio device throughharvesting of the RF signal communicating between cell phone 456 anddevice 474. In one embodiment, device 474 includes sensors 332 ofelectronic circuitry 310. Sensor 332 of device 474 is configured tomeasure one or more parameters. The parameters can then be reported tothe second wireless device such as cell phone 456 or other device incommunication with device 474. In one embodiment, device 474 can includea rechargeable battery. In one embodiment, harvested energy by device474 is used to recharge the rechargeable battery in device 474. Thesecond wireless device in communication with device 474 is configured torequest modulation of a transmit power of the transmission of the radiofrequency signal of the second wireless device to support continuousoperation of device 474.

Components of FIGS. 1-27 will be referred to when discussing a medicalsystem disclosed herein below for performing a task. The description ofFIGS. 1-27 are also included in any discussion of structure or operationherein below. The medical system includes a first medical device, asecond medical device, and a computer. The first medical device andsecond medical device can be in communication with each other. The firstor second medical device can also be in communication with the computer.In one embodiment, the first medical device is configured to be placedbelow the dermis. In one embodiment, the first medical device does nothave a power source. The first medical device harvests energy from oneor more radio frequency signals and stores the energy until enoughenergy is stored to complete a task. The first medical device includeselectronic circuitry 310 configured to perform the at least one task.The first medical device can have sensors 332 configured to measure oneor more parameters. Sensor 332 can also comprise one or more devicesconfigured to provide therapy, heal, or support rehabilitation. Thefirst medical device also includes IMU 330 that is configured to measureposition, location, and trajectory and operates with 9 degrees offreedom. In one embodiment, a module 396 comprises printed circuit board356 and electronic circuitry 310. The enclosure is sealed with a capthat isolates the electronic circuitry 310 from an external environment.In one embodiment, subcutaneous screw 380 comprises screw body 386 andscrew head 384. Screw body 386 is the enclosure and screw head 384 isthe cap to seal the enclosure from an external environment. Module 396is placed within cavity 388 of screw body 388 prior to sealing the capto the enclosure. At least a portion of screw body 388 has a threadedregion 390. In one embodiment, screw body 388 comprises a non-conductivematerial such as a plastic, polymer, or other biocompatible material. Inone embodiment, the cap comprises electrically conductive material. Thecap or screw head 384 is configured to couple to ground of electroniccircuitry 310 and a terminal of dual band antenna 312. In oneembodiment, subcutaneous screw 380 is configured to screw into a bone ofthe musculoskeletal system where it can be retained permanently or for apredetermined time (and then removed).

The first medical device is configured to be in communication with thesecond medical device or a computer. For example, subcutaneous screw 264(first medical device) is configured to communicate with patch device256 (second medical device) or computer 252 as shown. In one embodiment,the first medical device such as subcutaneous screw 264 includes dualband antenna 312 that couples to electronic circuitry 310. Electroniccircuitry 310, IMU, 330, sensors 332, and dual band antenna 312 areconfigured to fit within the cavity of the first medical device.Electronic circuitry 310 controls IMU 330 and sensors 332 measurementand transmits measurement data to patch device 256 or computer 252. Dualband antenna 312 of the first medical device comprises a first antennaand a second antenna. The first antenna is configured to operate withina first frequency band below 1 gigahertz. The second antenna isconfigured to operate with a second frequency band above one gigahertz.The first frequency band supports efficient transfer of energy beneathtissue of a body. The second frequency band utilizes many of the commonshort range communication protocols for transferring information ormeasurement data such as WiFi, Bluetooth, Zigbee, WiMax, or othercommunication standards. The first medical device can have more than 2antennas. Electronic circuitry 310 of the first medical device isconfigured to harvest energy received by dual band antenna 310 of thefirst medical device. Energy is harvested until operation of theelectronic circuitry 310 can be sustained to perform at least one task.In one embodiment, radio frequency signals coupled to dual band antenna312 are harvested, rectified, stored, converted to one or more voltagesto enable electronic circuitry to control a measurement process,transmit measurement data, and operate an orderly shutdown of electroniccircuitry 310.

Electronic circuitry 310 of the first medical device includes energystorage device 318. In one embodiment, energy storage device 318 of thefirst medical device is a super capacitor that is configured to receivethe harvested energy received by dual band antenna 312 of the firstmedical device. The first medical device includes a position, motion,and trajectory tracking system. In one embodiment, the position, motion,and trajectory system of the first medical device is IMU 330 having 9degrees of freedom. In one embodiment, electronic circuitry 310 is notenabled until a predetermined energy is stored on energy storage device318 of the first medical device.

In one embodiment, the first antenna of the first medical device is acoil antenna 402. Coil antenna 402 supports higher efficiency ofreceived signals by the first antenna of dual band antenna 312 of thefirst medical device. Coil antenna 402 is configured to fit within thecavity of the first medical device. In one embodiment, the secondantenna of dual band antenna 312 is formed on printed circuit board 356of module 396. Module 396 is configured to fit within coil antenna 402.Both coil antenna 402 and module 396 are retained within the cavity.

In one embodiment, first antenna 512 of dual antenna 312 of the firstmedical device is formed on a first side 502 of a dielectric substrate506. Second antenna 514 of dual antenna 312 of the first medical deviceis formed on a second side 504 of the dielectric substrate 506. Theconductor 508 of the first antenna of dual antenna 312 of the overliesthe conductor 510 of the second antenna of dual antenna 312 of the firstmedical device by 50 percent or less. Reducing overlap of conductors 508and 510 increases the efficiency of dual antenna 312 at the first andsecond operating frequency bands. In one embodiment, the cap comprisesan electrically conductive material. An electrode of first antenna 512of the first medical device is configured to couple to the electricallyconductive material of the cap. Similarly, an electrode of the secondantenna 514 of the first medical device is configured to couple to theelectrically conductive material of the cap.

In the example, of the first medical device the enclosure is a screwbody 386 and the cap is a screw head 384 forming subcutaneous screw 380.Screw body 386 has a cavity 388 that can receive module 396 and dualband antenna 312. Screw head 384 coupled to screw body 386 forms ahermetic seal of cavity 388. In one embodiment, the first medical deviceis a passive device that does not have a power source. Operation isenabled by harvesting energy from a radio frequency signal. The exampleof the first medical device shows that the enclosure and the cap offirst medical device can take many different forms and shapes dependingon the application and where it is placed below the dermis. Subcutaneousscrew 380 as the first medical device is configured to couple to themusculoskeletal system and more specifically can be screwed into a boneof the musculoskeletal system for performing a task such as positiontracking, measurement of one or more parameters, providing a therapy, orsupporting rehabilitation. In one embodiment, screw body 386 can haveone or more openings or one or more sealed opening. The one or moreopenings can provide access for a sensor or device within the firstmedical device to measure an external environment, provide therapy, orrehabilitate. The sealed openings can provide a path for one or moresignals. For example, the one or more openings of screw body 386 can besealed with a material that is transmissive to different frequencylight. The light can be used for measurement, therapy, orrehabilitation.

In one embodiment, a washer 164 is configured to couple to a screw.Washer 164 can include electronic circuitry 310 and dual band antenna312 of FIG. 10. Washer 164 is configured to harvest energy of one ormore radio frequency signals received by dual band antenna 312 in washer164 as disclosed herein above for electronic circuitry 310. Theharvested energy of washer 164 enables operation of electronic circuitry310 within washer 164 to perform at least one task such as performing ameasurement, providing therapy, or supporting rehabilitation. Washer 164couples to a head of the screw and distributes a force from the screwhead to an area of a surface of washer 164 thereby reducing the forceper unit area. In one embodiment, washer 164 can couple to subcutaneousscrew 380.

In one embodiment, a plate 190 is configured to couple to one or morescrews or one or more washers. Plate 190 can include electroniccircuitry 310 and dual band antenna 312 of FIG. 10. Plate 190 isconfigured to harvest energy of one or more radio frequency signalsreceived by dual band antenna 312 in plate 190 as disclosed herein abovefor electronic circuitry 310. The harvested energy of plate 190 enablesoperation of electronic circuitry 310 within plate 190 to perform atleast one task such as performing a measurement, providing therapy, orsupporting rehabilitation. Plate 190 couples to a head of the screw or awasher and distributes a force from the screw head or washer to an areaof a surface of plate 190 thereby reducing the force per unit area. Inone embodiment, plate 190 can couple to subcutaneous screw 380 or washer164.

The second medical device of the medical system comprises a flexibleenclosure, electronic circuitry 310, a power source coupled to theelectronic circuitry, and a dual band antenna. In one embodiment, thesecond medical device is patch device 256 as shown in FIG. 8. Patchdevice 256 is a device 350 as shown in more detail in FIG. 11 as device350. In the example, patch device 256 or device 350 will be referred tointerchangeably as the second medical device of the medical system. Inone embodiment, patch device 256 is over-molded with a flexible materialsuch as silicone to form a flexible enclosure around the power source,module 396, and dual antenna 312. Device 350 comprises module 396,battery 360, and printed circuit board 358. Module 396 comprises printedcircuit board 356 and electronic circuitry 310. In one embodiment,battery 360 is a rechargeable battery. Battery 360 couples to module 396through interconnect on stripe 368 of flexible printed circuit board 358of the second medical device. Dual band antenna 312 of the secondmedical device comprises a first antenna 358 formed on flexible printedcircuit board 358 and a second antenna 364 is formed on printed circuitboard 356 of module 396. The large circumference of flexible printedcircuit board 358 supports a larger antenna to be formed for receivingsignals below 1 gigahertz. In one embodiment, patch device 256 has anadhesive system that couples patch device 256 to the skin in proximityto the first medical device to support efficient energy transfer. Notethat the second medical device has similar electronic circuitry and dualantenna system as the first medical device. A main difference betweenthe first and second medical devices is that the second medical devicehas battery 360 and the first medical device does not have a battery orpower source. Energy has to be harvested by the first medical device inorder for it to operate. The medical system is configured to have thesecond medical device transmit a radio frequency signal in a firstfrequency band to the first medical device. In the example, the firstantenna 358 of the second medical device is configured to transmit asignal to the first medical device. As mentioned the signal will bewithin a first frequency band less than 1 gigahertz. The first frequencyband supports the signal penetrating through tissue to the first medicaldevice. In one embodiment, the second medical device is configured totransmit the signal continuously thereby powering the first medicaldevice continuously. The first medical device such as subcutaneous screw262 is configured to be in communication with the first medical devicesuch as patch device 256 after the subcutaneous screw 262 has harvestedenough energy to enable electronic circuitry 310 within subcutaneousscrew 262. In one embodiment, the communication can occur at a secondfrequency band that supports the transmission of data or informationsuch as Bluetooth, WiFi, Zigbee, WiMax, or other standard protocols. Thesecond frequency band corresponds to the second antenna 364 of device350. Subcutaneous screw 364 also has an antenna formed on printedcircuit board 356 of module 396 within the first medical device forcommunicating with the second medical device. The first and secondmedical devices can be in communication with each other or otherdevices. For example, the first and second medical devices can be incommunication with computer 252. The first and second medical devicescan also be in communication with other similar devices if implanted orplace in proximity to the first and second medical devices.

Components of FIGS. 1-27 will be referred to when discussing a medicalsystem disclosed herein below for performing a task. The description ofFIGS. 1-27 are also included in any discussion of structure or operationherein below. A medical system comprises a patch device 256, a computer252, and a device. The patch device 256 of FIG. 8 is shown as device 350in FIG. 11. Patch device 256 or device 350 will be used interchangeablein disclosing operation or components therein. In one embodiment, patchdevice 256 comprises a module 396, a battery 360, an antenna system, anda printed circuit board 358. In one embodiment, patch device 256 isconfigured to be similar to a bandage that can be coupled to the skin totake measurement, provide a therapeutic benefit, or be in communicationwith the device. Module 396 comprises a printed circuit board 356 andelectronic circuitry 310. Electronic circuitry 310 is disclosed in FIG.310. Electronic circuitry 310 includes an IMU 330 and sensors 332.Sensors 332 can be configured to measure one or more parameters. Sensors332 can also comprise one or more devices for providing a therapy,support healing, or rehabilitate. IMU 33 is coupled to the electroniccircuitry and is configured to measure position, movement, andtrajectory of patch device 256. In one embodiment, the antenna system isconfigured to harvest energy from one or more radio frequency signalsreceived by the antenna system. In one embodiment, electronic circuitry310 is configured to recharge battery 360 with the harvested energy fromthe one or more radio frequency signals. For example, a radio frequencysignal from computer 252 to patch device 256 can be harvested. The radiofrequency signal is also a communication path for information betweencomputer 252 and patch device 256. Package 366 of patch device 256comprises a flexible enclosure. The flexible enclosure of package 366 isconfigured to couple to a non-planar surface. In one embodiment, patchdevice 256 comprises an area 50 millimeters by 25 millimeters or less.In one embodiment, package 366 is configured to couple to skin similarto a bandage. In one embodiment package 366 is less than 4 millimetersthick. In one embodiment, battery 360 is a flexible battery configuredto conform to a shape of a surface to which the patch device couples.

Electronic circuitry 310 further comprises radio frequency to DC radiorectifier circuit 316, energy storage device 318, and DC-DC converter320. Radio frequency to DC radio rectifier circuit 316, energy storagedevice 318, and DC-DC converter 320 support harvesting the energy fromthe one or more radio frequency signals, storing the energy, andproviding one or more voltages for enabling electronic circuitry 310.Patch device 256 includes transceiver and control circuit 322. Thetransceiver can couple to other devices having electronic circuitry 310or a computer such as computer 252. Control circuitry within transceiverand control circuit 322 controls a measurement process or manages atherapy. Transceiver and control circuit 322 is configured tocommunicate to other devices or computer 252 to provide measurementdata, information related to therapy, or motion information. In oneembodiment, the antenna system of patch device 256 comprises a dual bandantenna 312. Antenna 362 is formed on printed circuit board 358 where atleast a portion of a conductor of antenna 362 has a serpentine shape. Inone embodiment, antenna 362 of patch device 256 is formed around aperiphery of printed circuit board 368. Printed circuit board 368 isflexible and conforms to non-planar surfaces. Antenna 362 is configuredto operate in a first frequency band that is less than 1 gigahertz infrequency. Antenna 364 of dual band antenna 312 is formed on printedcircuit 356 of module 396 in patch device 256. Antenna 364 fits in lessarea than antenna 362 and is configured to operate in a frequency bandgreater than 1 gigahertz. In one embodiment, the frequency band ofantenna 362 does not overlap the frequency band of antenna 364. In oneembodiment, a majority of electronic circuitry 310 is coupled to printedcircuit board 356. In one embodiment, all of electronic circuitry 310 iscoupled to printed circuit board 356 of module 396. Printed circuitboard 356 comprises less area than printed circuit board 358. Thissupports migrating module 396 for different device applications, lowermanufacture costs, increase volume, simplify assembly and packaging.Electronic circuitry 310 is configured to perform the at least one taskand transmit information related to the at least one task. In oneembodiment, battery 360 and module 396 of patch device 256 is placed onprinted circuit board 358 along a long axis. Battery 360 and module 360would be placed centrally along the 50 millimeter length long axis ofpatch device 256. In one embodiment, a stripe 368 of printed circuitboard 358 is formed on the long axis of patch device 256. Battery 360,module 396, and antenna 362 couple to interconnect on stripe 368 to formpatch device 256. Package 366 forms the enclosure around printed circuitboard 358, battery 360, and module 396 of patch device 256. In oneembodiment, package 366 comprises silicone and is molded to seal printedcircuit board 358, battery 360, and module 396 from an externalenvironment.

Patch device 256 is configured to couple to a non-planar surface. In theexample, patch device 256 is configured to couple to skin in proximityto a second device. In one embodiment, patch device 256 includes anadhesive system. The adhesive system 410 couples to patch device 256.Adhesive system 410 includes a cover that is removed to expose anunderlying adhesive layer to couple patch device 256 to a surface. Patchdevice 256 is configured to transmit a radio frequency signal to a screw264 or computer 252. In the example, screw 264 is a device havingelectronic circuitry 310 and the antenna system but no power source. Theradio frequency signal transmitted by patch device 256 is harvested byscrew 264. After a predetermined amount of energy is stored within screw264, electronic circuitry 310 of screw 264 is enabled to perform atleast one task such as taking a measurement with one or more sensors orprovide a therapy support healing or rehabilitation by a device therein.In one embodiment, screw 264 can be operated continuously with anuninterrupted radio frequency signal from patch device 256. In oneembodiment, screw 264 in communication with patch device 256 can requesta change in transmit power of the radio frequency signal from patchdevice 256. Screw 264 can request an increase or decrease in transmitpower to modulate the transmit power to adjust the energy harvested byscrew 264 thereby keeping screw adequately powered to perform one ormore tasks. In one embodiment, medical patch 256 includes a dual bandantenna 312 comprising a first antenna 512 formed on a first side 502 ofa dielectric substrate 506 and a second antenna 514 formed on a secondside 504 of dielectric substrate 506. A conductor 508 of the firstantenna 512 overlies a conductor 510 of the second antenna 514 by lessthan 50 percent.

In one embodiment patch device 256 is in communication with computer252. A WiFi router 468 or Bluetooth network 460 can supportcommunication between patch device 256 and computer 252. At least oneradio frequency signal is harvested by patch device 256 to rechargebattery 360 within patch device 256. Patch device 256 can be used tomonitor a wound and support healing of the wound. Patch device 256 cancome in different sizes to cover a wound. In general, the adhesivesystem 410 of patch device 256 couples to a wound area. In oneembodiment, the adhesive system 410 overlies the wound and seals patchdevice 256 to the wound area thereby isolating the wound area from anexternal environment. Sensors 332 of patch device 256 includes at leastone camera. At least one task of patch device 256 is to continuously,periodically, or randomly monitor the wound. Pictures or video frompatch device 256 can be transmitted to computer 252 continuously,periodically, or randomly. Computer 252 can include software to analyzephoto or video information on the wound. In one embodiment, computer 252can send out an alert to indicate a positive or negative change in woundstatus to the patient or medical staff. Computer 252 can also send woundinformation to the medical staff for their interpretation and feedbackon care for the wound. Sensors 332 of patch device 256 can include atleast one of a temperature sensor, a pH sensor, a humidity sensor, apressure sensor, a MEMs sensor, a chemical sensor, photo diode, ultraviolet diodes, light emitting diodes, photo detectors, a transducer or abiosensor to support monitoring the wound or providing treatment to thewound. For example, certain types of light or a signal of apredetermined frequency or amplitude can provide therapy to the wound.

In one embodiment, a plurality of patch devices 256 can be used toperform wireless electrocardiography. Sensors 332 of each patch device256 includes one or more electro-cardiogram electrodes configured todetect electrical activity generated by heart muscle depolarizations.The heart muscle depolarizations generate pulsating electrical wavesthat are received by the electro-cardiogram electrodes. Theelectro-cardiogram electrode or electrodes of patch device 256 areexposed for coupling to the skin. Adhesive system 410 holds theelectro-cardiogram electrode or electrodes to the skin for detecting theelectrical activity. In one embodiment, at least four patch devices 256are used for an electrocardiogram. The four patch devices 256 areconfigured to be placed a predetermined locations to the skin of thepatient. Each patch device 256 has the same circuitry andelectro-cardiogram electrodes. In one embodiment, computer 252 hasmultiple channels for communication. Each patch device 256 is configuredto couple to a different communication channel. For example, eachchannel can be configured for Bluetooth device pairing such that eachpatch device 256 is paired to a channel of computer 252. Computer 252receives the information from each patch device and can display theelectrocardiographic data. Computer 252 can further analyze themeasurement data and indicate points of interest or concern.

Patch device 256 can be configured for photoplethysmography. Patchdevice 256 is a wireless system for detecting blood volume changes intissue. Patch device 256 can be used to detect a signal through tissueor a signal reflected back after going through tissue. For example,patch device 256 can be wrapped around a finger where a light sourcesensor is on one side of the finger and a light detector is on anopposing side of the finger. Patch device 256 is flexible and adhesivesystem 410 will couple patch device to the skin as it is wrapped aroundthe finger. Alternatively, patch device 256 can have the light sourcesensor and the photo diode placed to detect reflected signals such thatpatch device 256 does not require wrapping around the finger. Asmentioned sensors 332 includes a light source and a photo detector. Thelight source is configured to transmit a light signal into tissue. Thephoto detector is positioned to receive light transmitted through thetissue or reflected off the tissue. The measurement data from the photodetector is transmitted to computer 252. Computer 252 is configured touse the photo detector measurement data to measure heart rate,inter-beat interval, or heart-rate variability, as well as other heartmeasurements.

Components of FIGS. 1-27 will be referred to when discussing a medicalsystem disclosed herein below for performing a task. The description ofFIGS. 1-27 are also included in any discussion of structure or operationherein below. An orthopedic system for pre-operative, intra-operativeand post-operative measurement is disclosed herein. The orthopedicsystem comprises a screw 274, a screw 276, and a computer 278. In oneembodiment, screw 274 and the screw 276 do not have an internal powersource. The screw 274 is configured to couple to a first bone of amusculoskeletal system and the screw 276 is configured to couple to asecond bone of the musculoskeletal system. In the example, screw 274 iscoupled to a femur 270 and screw 276 is coupled to a tibia 272. Openingsare drilled in the femur 270 and tibia 272 to respectively receivescrews 274 and 276. In one embodiment, screws 274 and 276 are configuredto monitor a knee joint of a leg. Although the knee joint is used as anexample screws 274 and 276 can be mounted in two different bones tomonitor movement of a joint of the musculoskeletal system or two bonesrelative to one another. Thus, screws 274 can be used to monitor a kneejoint, hip joint, shoulder joint, spine, ankle, wrist, fingers, or toesas an example. The position and location of screws 274 and 276 areprecisely known relative to bone landmarks or location of the specificfemur and tibia to which they are attached. The position and location ofscrews 274 and 276 can be identified precisely using pictures or scansof the musculoskeletal system. The position and location information isprovided to computer 278. Computer 278 includes one or more softwareprograms that use measurement data from screws 274 and 276 to assess ajoint of the musculoskeletal system, support surgical repair, or supportinstallation of one or more prosthetic components. Screw 274 isconfigured to harvest radio frequency energy to enable electroniccircuitry 310 within screw 274 to perform at least one task. Electroniccircuitry 310 within screw 274 includes one or more sensors 332 and anIMU 330 to provide position, movement, and trajectory information.Sensors 332 can include devices for providing a therapy, supporthealing, or rehabilitation. Examples of devices within sensors 332 arepain mitigation, bone density support, infection support, bone fracturerepair, and other therapies that can be provided locally by screws 274and 276. Similarly, second screw 276 is configured to harvest radiofrequency energy to enable electronic circuitry 310 within screw 276 toperform at least one task. Electronic circuitry 310 within screw 276includes sensors 332 and IMU 330 similar to that disclosed for screw274. Computer 278 is configured to receive measurement data from screws274 and 276. IMU 330 in screws 274 and 276 are configured to monitormovement of the first bone relative to the second bone which is includedin the measurement data sent to computer 278. The one or more tasksperformed by screws 274 and 276 can comprise generating measurement dataor performing a therapy as disclosed herein above. The one or more tasksperformed by screws 274 and 276 and the measurement data from screws 274and 276 are used by computer 278. Computer 278 includes one or moresoftware programs that can use the measurement data from screws 274 and276 to provide information related to alignment, range of motion,loading, impingement, contact points, movement, translation, kineticassessment, balance, stability, rotation, graft adherence, graftfailure, exercises assessment, muscle strength, gait analysis,proprioception, or functional healing to name but a few that theorthopedic system can support analysis of. Computer 278 and display 280can be configured to provide the information in a manner that supportsrapid assimilation of measurement data through graphics, audible, orhaptic means.

IMU 330 of screw 274 and IMU 330 of screw 276 are zeroed relative togravity to support accurate position, movement, and trajectorymeasurement. IMU 330 of screw 274 and IMU 330 of screw 276 are zeroedrelative to each other. Computer 278 has a position or location of thescrew 274 relative to femur 270. Similarly, computer 278 has a positionor location of screw 276 relative to tibia 272. Measurement data fromIMU 330 of screw 274 and measurement data from IMU 330 of screw 276 isprovided to computer 278 once screws 274 and 276 are enabled. In oneembodiment, computer 278 can include multiple channels for connecting toscrews 274 and 276 such that both can be providing informationsimultaneously in real-time. Computer 278 is configured to calculate aposition of femur 270 relative to tibia 272 in real-time frommeasurement data respectively from screw 274 and screw 276.

In one embodiment, a device 282 and a device 284 are respectively placedin proximity to screw 274 and screw 276. For example, devices 282 and284 can be coupled to the skin of the leg with an adhesive.Alternatively, devices 282 and 284 can be in a brace or sleeve that whenworn around the knee joint will locate devices 282 and 284 in proximityto screws 274 and 276. Device 282 and device 284 each include a powersource. In one embodiment, device 282 and device 284 each have arechargeable battery 360. In one embodiment, device 282 and device 284transmit a radio frequency signal in a band below 1 gigahertzrespectively to screw 274 and screw 276. Screws 274 and 276 respectivelyharvest energy from the radio frequency signal in a frequency band below1 gigahertz from device 282 and device 284. After a predetermined amountof energy is stored by energy storage device 318 in screw 274, screw 274is enabled to perform at least one task. Similarly, screw 276 is enabledto perform at least one task after a predetermined amount of energy isstored by energy storage device 318 in screw 276. Computer 278 isconfigured to report position, motion, or rotation of femur 270 or tibia272 using measurement data from screw 274 or screw 276. Computer 278 canalso process movement of femur 270 and tibia 272 relative to oneanother. Movement or location information can be reported on display 280of computer 278 in a surgical environment or post-operatively. Computer278 is configured to assess aspects of a knee joint of a leg such asalignment, range of motion, extension, and flexion. Computer 278 recordsmovement of femur 270 and tibia 272 as the leg is moved through one ormore different motions using measurement data from screw 274 and screw276.

In one embodiment, an anterior-posterior drawer is performed on the kneejoint. Computer 278 is configured to measure translation anddisplacement relative to screws 274 and 276 from the measurement datafrom screws 274 and 276. In general, the measurement is used todetermine if there is excessive posterior translation in the knee joint.The amount of posterior translation can be disclosed or indicated ondisplay 280 of computer 278. In one embodiment, a Lachman Test isperformed on the knee joint. Computer 278 is configured to assess theanterior motion of the tibia to define ACL stability from themeasurement data received from screws 274 and 276. The assessment can bedisclosed on display 280 of computer 278. In one embodiment,medial-lateral forces can be applied to the knee joint at 20 degrees.The forces can be applied by a device that measures the applied forces.In one embodiment, computer 278 receives an approximate applied force.The computer is configured to assess the collateral ligament stabilityfrom measurement data from screw 274 and screw 276. The assessment ofcollateral ligament stability can be displayed on display 280 ofcomputer 278.

Computer 278 can be configured for post-operative monitoring of the kneejoint using measurement data from screw 274 and screw 276. In oneembodiment, a post-operative exercise regimen is prescribed to apatient. Screw 274 and screw 276 can be enabled during an exercisesession. The patient post-operative exercise regimen is compared tomonitored movement of the knee joint by measurement data from screw 274and screw 276. Screw 274 and 276 provides the measurement data tocomputer 278. Computer 278 receives and uses the measurement data toprovide an assessment, rehabilitation report or workflow forimprovement. The leg can be placed in a defined extension maneuver withan applied resistance. A device can be used to measure and apply theresistance. The applied resistance is provided to computer 278. Computer278 is configured to measure quadriceps strength and torque usingmeasurement data from screws 274 and 276 knowing the extension maneuverand the applied resistance. Computer 278 can display the quadricepsstrength and torque on display 280. Screws 274 and 276 can be enabled tomonitor the leg in motion under normal walking or running conditions.Movement of the leg is monitored using measurement data from screw 274and 276. Computer 278 receives the measurement data and assesses gaitmechanics such as stride, cadence, activity, steps, and other movement.Computer 278 can report on the gait mechanics. Computer 278 can alsoprovide an improvement plan based on the measurement data from screws274 and 276. Furthermore, a knee exam can be performed with measurementdata from screw 274 and screw 276 in real-time for activities such aswalking, running, acceleration, or deceleration. The computer isconfigured to assess final healing of the knee joint from themeasurement data doing the above mentioned activities. The computer canalso provide a plan or work flow for continued improvement or determineareas of concern if the knee joint has not healed based on theassessment.

Components of FIGS. 1-27 will be referred to when discussing a medicalsystem disclosed herein below for performing a task. In one embodiment,the medical system is an orthopedic medical system. The description ofFIGS. 1-27 are also included in any discussion of structure or operationherein below. An orthopedic system for pre-operative, intra-operative,and post-operative measurement comprises a computer 278, a device 282, adevice 284, a screw 274, and screw 276. Device 282, device 284, screw274, and screw 276 each have electronic circuitry 310. In oneembodiment, device 282, device 284, screw 274, and screw 276 each havean IMU 330 for position and motion tracking. Device 282, device 284,screw 274, and screw 276 may not have the same sensors 332, each canhave it's own complement of unique sensors for measuring one or moreparameters. Sensors 332 can also include devices configured forproviding a therapy, healing, pain mitigation, or to supportrehabilitation. Device 282 and device 284 include a power source such asa battery. Screw 274 and screw 276 are passive devices requiring energyto be provided before being enabled to perform at least one task. In oneembodiment, device 282, device 284, or both can be used with computer278 to perform a task related to the musculoskeletal system. In oneembodiment, computer 278, device 282, device 284, screw 274, and screw276 are configured to perform a task related to the musculoskeletalsystem.

Device 282 is configured to couple to a first bone of a musculoskeletalsystem. Device 282 has an antenna system configured for transmitting andreceiving information or measurement data. Device 282 is configured toharvest energy from at least one radio frequency signal received by theantenna system of device 282. In one embodiment, the antenna system is adual band antenna 312. Device 282 includes an IMU 330 configured tomeasure movement or location of device 282.

Device 284 is configured to couple to a second bone of a musculoskeletalsystem. Device 284 has an antenna system configured for transmitting andreceiving information or measurement data. Device 284 is configured toharvest energy from at least one radio frequency signal received by theantenna system of device 284. In one embodiment, the antenna system ofdevice 284 is a dual band antenna 312. Device 284 includes an IMU 330configured to measure movement or location of device 282. Computer 278is configured to receive measurement data from device 282 or device 284.Devices 282 and 284 are configured to monitor movement of the firstbone, the second bone, or the first bone in relation to the second bone.Device 282 and device 284 can have an adhesive system configured tocouple device 282 or device 284 to a surface or skin. In one embodiment,device 282 and device 284 are flexible to couple to a non-planar surfaceor a contour. Alternatively, device 282 and device 284 can part of abrace, wrap, or sleeve to be used with the musculoskeletal system. Thebrace, wrap, or sleeve couples to the musculoskeletal system placingdevice 282 and device 284 on or near the skin. In one embodiment, thebrace or wrap places devices 282 and 284 at predetermined locations thatcan respectively be related to the first bone and the second bone.

In one embodiment, IMU 330 of device 282 and IMU 330 of device 284 arezeroed relative to gravity. In one embodiment, IMU 330 of device 282 andIMU 330 of device 284 are also zeroed relative to each other.Measurement data from IMU 330 of device 282 and measurement data fromIMU 330 of device 284 is transmitted to computer 278. Computer 278 isconfigured to use the measurement data to track the positions of devices282 and 284 and display movement or location on display 280. In oneembodiment, computer 278 has a position of device 282 relative to thefirst bone. Similarly, computer 278 has a position of device 284relative to the second bone. In one embodiment, computer 278 cantranslate the positions of devices 282 and 284 relative to the firstbone and the second bone to track movement of the first bone and thesecond bone. Computer 278 is configured to calculate a position of thefirst bone relative to the second bone in real-time using measurementdata from devices 282 and 284.

In one embodiment, computer 278 is configured to report position,motion, or rotation of the first bone or the second bone usingmeasurement data from the first device or the second device. Theposition, motion, or rotation of the first bone or the second bone isconfigured to be displayed on display 280. In one embodiment, theorthopedic system is used pre-operatively to generate pre-operativemeasurement data using device 282 and device 284. The pre-operativemeasurement data is relate to the first bone and the second bone. In oneembodiment, computer 278 is configured to use data analytics and thepre-operative measurement data to support a surgical solution. I

In one embodiment, the orthopedic system is used post-operatively togenerate post-operative measurement data during a rehabilitationprocess. The rehabilitation process comprises one or more exercises.Devices 282 and 284 generate the post-operative data as a patientperforms the one or more exercises and provides the post-operativemeasurement data to computer 278. The post-operative measurement data isconfigured to be displayed on display 280 to indicate progress inrehabilitation. Computer 278 can adjust a regimen for rehabilitationbased on the post-operative measurement data. In general, thepost-operative measurement data from device 282 and device 284 isconfigured to be used by computer 278 in an assessment to determineresumption of normal activities. Computer 278 can include a program thatuses the post-operative measurement data to support the determinationwhether the patient is healed.

In one embodiment, the first bone is a femur 270 and the second bone isa tibia 272. Although the example relates to a knee joint and aninstallation of a prosthetic knee, the concept can be used anywhere onthe musculoskeletal system and more specifically on joints of themusculoskeletal system where one bone moves in relation to a secondbone. The orthopedic system can be used on joints of the musculoskeletalsystem such as the spine, hip, shoulder, ankle, elbow, hand, foot,ankle, or wrist. Computer 278 is configured to assess the knee joint ofthe leg using measurement data from devices 282 and 284. Computer 278uses the measurement data from devices 282 and 284 to record a range ofmotion, full extension, flexion, and rotation of the knee joint as theleg is moved through one or more different motions. Other parameters asdisclosed herein above can be measured using sensors 332 on device 282or device 284 and reported to computer 278 or used in a calculation ofan assessment.

In one embodiment, an anterior-posterior drawer is performed on the kneejoint. Computer 278 is configured to measure a translation anddisplacement relative to device 282 and device 284 from the measurementdata. The translation and displacement of devices 282 and 284respectively can be converted to movement of femur 270 or tibia 272. Theresults of the anterior-posterior drawer can be displayed on display280. In one embodiment, a Lachman Test is performed on the knee joint.Computer 278 is configured to assess the anterior motion of the tibia todefine an ACL stability from the measurement data from the devices 282and 284. As mentioned previously, movement devices 282 and 284respectively can be converted to movement of femur 270 or tibia 272. Thestability of the ACL can be calculated and displayed on display 280. Inone embodiment, computer 278 is configured for pre-operative monitoringof the knee joint. Computer 278 uses measurement data from devices 282and 284 to measure gait mechanics. The gait mechanics from themeasurement data is used by computer 278 to support a rehabilitationprogram or a surgical solution. For example, the gait mechanics canindicate that improvement of the leg function could be achieved throughexercise, an external brace, or strengthening specific muscles withoutthe need for surgery. Computer 278 can suggest a work flow or exerciseprogram to improve specific elements of the gait mechanics andrehabilitate the knee. Conversely, the gait mechanics analyzed bycomputer 278 can indicate that a surgical solution is required as theknee joint or parts of the knee joint may be degraded to a point wherereplacement is required. Computer 278 can analyze a surgical solutionbased on the gait mechanics and suggest specific bone cuts, prostheticcomponents, or installation strategies that will improve the gaitmechanics after a prosthetic knee is installed.

Computer 278 can be configured for post-operative monitoring of the kneejoint using measurement data from devices 282 and 284. In general,computer 278 can take many different forms. Computer 278 can be adesktop computer, a handheld device, a tablet, a cell phone, or anydevice having one of digital circuitry, control logic, microcontroller,a processor, or a digital signal processor. Devices 282 and 284 can beincorporated in a brace, wrap, or sleeve that is configured to couple tothe leg placing devices 282 and 284 at predetermined locations. Devices282 and devices 284 can include sensors 332 configured to monitor asurgical wound, detect infection, support pain mitigation, or promotebone healing. In one embodiment, a post-operative exercise regimen isprescribed. Computer 278 has the post-operative exercise regimen thatcan be provided to a patient. Measurement data from devices 282 and 284received by computer 278 can be related to specific exercises. In oneembodiment, an application using measurement data from devices 282 and284 is configured to monitor progress of the post-operative exerciseregimen. Computer 278 is configured to provide feedback on progressbased on the measurement data to the patient or medical staff. In oneembodiment, the leg is configured to be placed in a defined extensionmaneuver with an applied resistance. The amount of applied resistancecan be measured and provided to computer 278. Computer 278 is configuredto receive measurement data related to the extension maneuver andconfigured to calculate one or more muscle strength measurements. In oneembodiment, computer 278 is configured to measure quadriceps strengthand torque using measurement data from devices 282 and 284. In oneembodiment, computer 278 is configured to monitor movement of the legusing devices 282 and 284. Computer 278 can assess gait mechanics suchas stride, cadence, activity, steps, and other movement using themeasurement data. Computer 278 is configured to provide feedback or animprovement plan based on the measurement data. In one embodiment, aknee exam is performed on the knee joint. Devices 282 and 284 areconfigured to provide the measurement data to computer 278 related toone or more predetermined leg tests. The measurement data measures atleast one of range of motion, balance, stability, rotation, graftadherence, proprioception, gait mechanics, or muscle strength that isused to determine if the knee joint is healed. Computer 278 isconfigured to assess if the knee joint is healed from the measurementdata related to the one or more predetermined leg tests. Computer 278can provide the assessment to a doctor or medical staff for furtherreview.

While the present invention has been described with reference toparticular embodiments, those skilled in the art will recognize thatmany changes may be made thereto without departing from the spirit andscope of the present invention. Each of these embodiments and obviousvariations thereof is contemplated as falling within the spirit andscope of the claimed invention, which is set forth in the claims. Whilethe subject matter of the invention is described with specific examplesof embodiments, the foregoing drawings and descriptions thereof depictonly typical embodiments of the subject matter and are not therefore tobe considered to be limiting of its scope, it is evident that manyalternatives and variations will be apparent to those skilled in theart. Thus, the description of the invention is merely descriptive innature and, thus, variations that do not depart from the gist of theinvention are intended to be within the scope of the embodiments of thepresent invention. Such variations are not to be regarded as a departurefrom the spirit and scope of the present invention.

While the present invention has been described with reference toembodiments, it is to be understood that the invention is not limited tothe disclosed embodiments. The scope of the following claims is to beaccorded the broadest interpretation so as to encompass allmodifications, equivalent structures and functions. For example, ifwords such as “orthogonal”, “perpendicular” are used the intendedmeaning is “substantially orthogonal” and “substantially perpendicular”respectively. Additionally although specific numbers may be quoted inthe claims, it is intended that a number close to the one stated is alsowithin the intended scope, i.e. any stated number (e.g., 90 degrees)should be interpreted to be “about” the value of the stated number(e.g., about 90 degrees).

As the claims hereinafter reflect, inventive aspects may lie in lessthan all features of a single foregoing disclosed embodiment. Thus, thehereinafter expressed claims are hereby expressly incorporated into thisDetailed Description of the Drawings, with each claim standing on itsown as a separate embodiment of an invention. Furthermore, while someembodiments described herein include some but not other featuresincluded in other embodiments, combinations of features of differentembodiments are meant to be within the scope of the invention, and formdifferent embodiments, as would be understood by those skilled in theart.

What is claimed is:
 1. A wireless system comprising: a first wirelessdevice configured to operate with less than 15 milliamperes of currentand wherein the first wireless device includes an antenna system; and asecond wireless device having a power source wherein the second wirelessdevice is configured to transmit one or more radio frequency signals tothe first wireless device, wherein the antenna system of the firstwireless device is configured to the receive the one or more radiofrequency signals from the second wireless device, wherein the firstwireless device is configured to harvest energy from the one or moreradio frequency signals, wherein the first wireless device is enabledfor operation after a predetermined amount of energy is harvested fromthe one or more radio frequency signals, wherein a communicationhandshake occurs between the first and second wireless devices toindicate that the first wireless device is in communication with secondwireless device, and wherein the first wireless device is configured toperform at least one task from the energy harvested.
 2. The wirelesssystem of claim 1 wherein the first wireless device is configured tocommunicate with the second wireless device to modulate a transmit powerof the second medical device to support continuous operation of thefirst wireless device.
 3. The wireless system of claim 2 wherein anenergy storage device of the first wireless device stores the harvestedenergy of the one or more radio frequency signals and wherein the energystored on the energy storage device is monitored to support modulationof the transmit power of the second wireless device.
 4. The wirelesssystem of claim 3 wherein beam forming is used to increase transmitpower from the second wireless device.
 5. The wireless system of claim 1wherein the first wireless device is configured to charge a battery withthe harvested energy from the first signal thereby eliminating a batterycharging station for the first wireless device.
 6. The wireless systemof claim 1 wherein the antenna system of the first wireless devicecomprises two or more antennas operating at two or more frequency bandsand wherein the two or more frequency bands are non-overlapping.
 7. Thewireless system of claim 6 wherein the second wireless device transmitsat a first frequency band to provide energy to the first wireless deviceand wherein the second wireless device communicates to the firstwireless device through a second frequency band.
 8. The wireless systemof claim 1 wherein the first wireless device is configured to harvestenergy from any signal received by the antenna system.
 9. The wirelesssystem of claim 1 wherein the antenna system is a dual band antenna,wherein a first antenna is formed on a first side of a substrate,wherein a second antenna is formed on a second side of the substrate,and wherein the first antenna and the second antenna operate atdifferent non-overlapping frequencies.
 10. The wireless system of claim7 wherein a conductor of the first antenna and a conductor of the secondantenna overlap less than 50 percent.
 11. The wireless system of claim 1wherein the electronic circuitry includes an IMU to support positionlocation.
 12. The wireless system of claim 1 wherein the electroniccircuitry includes a radio frequency to DC radio rectifier circuit, anenergy storage device, and a DC-DC converter.
 13. The wireless system ofclaim 1 wherein the first wireless device is configured to provide audioand wherein the second wireless device is a cell phone.
 14. The wirelesssystem of claim 1 wherein the first wireless device includes one or moresensors configured to measure one or more parameters and wherein the oneor more parameters are reported to the second wireless device.
 15. Awireless system comprising: a first wireless device wherein the firstwireless device includes an antenna system and wherein the firstwireless device includes a rechargeable battery; and a cell phonewherein the cell phone is configured to transmit a signal to the firstwireless device, wherein the antenna system of the first wireless deviceis configured to receive the signal and communicate with the cell phone,wherein the first wireless device is configured to harvest energy fromthe signal, wherein the harvested energy from the signal is used tocharge the rechargeable battery, and wherein the first wireless deviceis configured to communicate with the second wireless device to modulatea transmit power of the second medical device to support continuousoperation of the first wireless device.
 16. The wireless system of claim15 wherein electronic circuitry of the first wireless device includes aradio frequency to DC radio rectifier circuit, an energy storage device,and a DC-DC converter.
 17. The wireless system of claim 15 wherein thefirst wireless device is configured to provide audio and wherein thesecond wireless device is a cell phone.
 18. A wireless systemcomprising: a first wireless device configured to operate with less thanor equal to 10 milliamperes of current harvested from one or more radiofrequency signals wherein the first wireless device includes an antennasystem, wherein the antenna system is a dual band antenna, wherein afirst antenna of the antenna system is formed on a first side of asubstrate, wherein a second antenna of the antenna system is formed on asecond side of the substrate, and wherein the first antenna and thesecond antenna operate at different non-overlapping frequencies; and asecond wireless device wherein the second wireless device istransmitting the one or more radio frequency signals, wherein theantenna system of the first device is configured to receive the radiofrequency signal and harvest energy from the radio frequency signal,wherein the first wireless device is enabled after a predeterminedamount of energy is harvested from the first signal, wherein the firstwireless device is configured to store the harvested energy on a supercapacitor, wherein electronic circuitry within the first wireless deviceis enabled after the predetermined amount of energy is harvested,wherein a communication handshake occurs between the first and secondwireless devices to indicate that the first wireless device is incommunication with second wireless device, and wherein the secondwireless device is configured to operate continuously from the radiofrequency signal of the first wireless device.
 19. The wireless systemof claim 18 wherein the first wireless device is configured tocommunicate to the second wireless device to modulate power of the oneor more radio frequency signal depending on the distance between thefirst and second wireless devices.
 20. The wireless system of claim 18wherein the electronic circuitry of the first wireless device includes aradio frequency to DC radio rectifier circuit, an energy storage device,and a DC-DC converter and wherein a conductor of the first antennaoverlies a conductor of the second antenna 50 percent or less.